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Azulay G, Pasechnek A, Stadnyuk O, Ran-Sapir S, Fleisacher AM, Borovok I, Sigal N, Herskovits AA. A dual-function phage regulator controls the response of cohabiting phage elements via regulation of the bacterial SOS response. Cell Rep 2022; 39:110723. [PMID: 35443160 PMCID: PMC9043618 DOI: 10.1016/j.celrep.2022.110723] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 02/09/2022] [Accepted: 03/30/2022] [Indexed: 12/02/2022] Open
Abstract
Listeria monocytogenes strain 10403S harbors two phage elements in its chromosome; one produces infective virions and the other tailocins. It was previously demonstrated that induction of the two elements is coordinated, as they are regulated by the same anti-repressor. In this study, we identified AriS as another phage regulator that controls the two elements, bearing the capacity to inhibit their lytic induction under SOS conditions. AriS is a two-domain protein that possesses two distinct activities, one regulating the genes of its encoding phage and the other downregulating the bacterial SOS response. While the first activity associates with the AriS N-terminal AntA/AntB domain, the second associates with its C-terminal ANT/KilAC domain. The ANT/KilAC domain is conserved in many AriS-like proteins of listerial and non-listerial prophages, suggesting that temperate phages acquired such dual-function regulators to align their response with the other phage elements that cohabit the genome. Listeria monocytogenes strain 10403S harbors two phage elements in its chromosome The lytic response of the phage elements is synchronized under SOS conditions AriS, a dual-function phage regulator, fine-tunes the elements’ response under SOS Aris regulates both its encoding phage and the bacterial SOS response
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Affiliation(s)
- Gil Azulay
- The Shmunis School of Biomedicine and Cancer Research, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
| | - Anna Pasechnek
- The Shmunis School of Biomedicine and Cancer Research, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
| | - Olga Stadnyuk
- The Shmunis School of Biomedicine and Cancer Research, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
| | - Shai Ran-Sapir
- The Shmunis School of Biomedicine and Cancer Research, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
| | - Ana Mejia Fleisacher
- The Shmunis School of Biomedicine and Cancer Research, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
| | - Ilya Borovok
- The Shmunis School of Biomedicine and Cancer Research, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
| | - Nadejda Sigal
- The Shmunis School of Biomedicine and Cancer Research, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
| | - Anat A Herskovits
- The Shmunis School of Biomedicine and Cancer Research, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel.
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Lysnyansky I, Borovok I. The aadE*- sat4- aphA-3 Gene Cluster of Mycoplasma bovirhinis HAZ141_2 Undergoes Genomic Rearrangements Influencing the Primary Promoter Sequence. Antibiotics (Basel) 2021; 10:antibiotics10111335. [PMID: 34827273 PMCID: PMC8614714 DOI: 10.3390/antibiotics10111335] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2021] [Revised: 10/27/2021] [Accepted: 10/27/2021] [Indexed: 11/16/2022] Open
Abstract
The 54 kb GC-rich prophage region of Mycoplasma bovirhinis HAZ141_2 contains three structural 'compartments', one of which is a highly transmittable cluster of three genes, aadE-like (aadE*), sat4, and aphA-3. In this study, we characterized recombination events and their consequences occurred within the aadE*-sat4-aphA-3 containing region. Analysis of this region revealed direct repeats (DRs) of 155 and invert repeats (IRs) of 197 base pairs (bps) each, flanking and overlapping with the primary promoter P* located upstream of the aadE*. Two recombination events, including inversions via both 197 and 155-bp IRs (the latter become inverted after the initial 197-bp IRs associated inversion) and the excision of the aadE*-sat4-aphA-3 cluster, were confirmed. Inversion via 155-IRs results in changes within the P* promoter region. Using Escherichia coli JM109 carrying plasmids containing derivatives of the aadE*-sat4-aphA-3 cluster, we validated the expression of those genes from different promoters. Our results showed no difference in the minimal inhibitory concentrations (MICs) to kanamycin and neomycin and only 2-fold decrease in MIC (from 512 to 256 μg/mL) to nourseothricin between the wild type and a P* derivative promoter. However, the MICs to kanamycin and neomycin were at least 4-fold lower in the construct where aphA-3 expressed under its P2 promoter (128 µg/mL) in comparison to the construct where aphA-3 expressed under P1″ promoter located within the sat4 gene (512-1024 µg/mL). PCR confirmed the excision of the aadE*-sat4-aphA-3 cluster via 197- and 155-bp DRs, but no selection of antibiotic-sensitive M. bovirhinis were obtained after 100 passages in kanamycin-free medium.
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Affiliation(s)
- Inna Lysnyansky
- Mycoplasma Unit, Division of Avian Diseases, Kimron Veterinary Institute, Beit Dagan 50250, Israel
- Correspondence: or (I.L.); or (I.B.)
| | - Ilya Borovok
- The Shmunis School of Biomedicine and Cancer Research, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel Aviv 69978, Israel
- Correspondence: or (I.L.); or (I.B.)
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Feng J, Zhang J, Ma Y, Feng Y, Wang S, Guo N, Wang H, Wang P, Jiménez-Bonilla P, Gu Y, Zhou J, Zhang ZT, Cao M, Jiang D, Wang S, Liu XW, Shao Z, Borovok I, Huang H, Wang Y. Renewable fatty acid ester production in Clostridium. Nat Commun 2021; 12:4368. [PMID: 34272383 PMCID: PMC8285483 DOI: 10.1038/s41467-021-24038-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Accepted: 05/26/2021] [Indexed: 11/25/2022] Open
Abstract
Bioproduction of renewable chemicals is considered as an urgent solution for fossil energy crisis. However, despite tremendous efforts, it is still challenging to generate microbial strains that can produce target biochemical to high levels. Here, we report an example of biosynthesis of high-value and easy-recoverable derivatives built upon natural microbial pathways, leading to improvement in bioproduction efficiency. By leveraging pathways in solventogenic clostridia for co-producing acyl-CoAs, acids and alcohols as precursors, through rational screening for host strains and enzymes, systematic metabolic engineering-including elimination of putative prophages, we develop strains that can produce 20.3 g/L butyl acetate and 1.6 g/L butyl butyrate. Techno-economic analysis results suggest the economic competitiveness of our developed bioprocess. Our principles of selecting the most appropriate host for specific bioproduction and engineering microbial chassis to produce high-value and easy-separable end products may be applicable to other bioprocesses. Esters can be used as fuels and specialty chemicals for food flavoring, cosmetic and pharmaceutical industries. Here, the authors systematically engineer clostridia, including discovery and deletion of prophages to increase strain stability, for the production of butyl acetate and butyl butyrate from corn stover at low cost.
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Affiliation(s)
- Jun Feng
- Department of Biosystems Engineering, Auburn University, Auburn, AL, USA.,Center for Bioenergy and Bioproducts, Auburn University, Auburn, AL, USA
| | - Jie Zhang
- Department of Biosystems Engineering, Auburn University, Auburn, AL, USA.,Center for Bioenergy and Bioproducts, Auburn University, Auburn, AL, USA
| | - Yuechao Ma
- Department of Biosystems Engineering, Auburn University, Auburn, AL, USA.,Center for Bioenergy and Bioproducts, Auburn University, Auburn, AL, USA
| | - Yiming Feng
- Department of Food Science and Technology, Virginia Tech, Blacksburg, VA, USA
| | - Shangjun Wang
- Department of Biosystems Engineering, Auburn University, Auburn, AL, USA.,Center for Bioenergy and Bioproducts, Auburn University, Auburn, AL, USA
| | - Na Guo
- Department of Biosystems Engineering, Auburn University, Auburn, AL, USA.,Center for Bioenergy and Bioproducts, Auburn University, Auburn, AL, USA
| | - Haijiao Wang
- Department of Biosystems Engineering, Auburn University, Auburn, AL, USA.,Center for Bioenergy and Bioproducts, Auburn University, Auburn, AL, USA
| | - Pixiang Wang
- Department of Biosystems Engineering, Auburn University, Auburn, AL, USA.,Center for Bioenergy and Bioproducts, Auburn University, Auburn, AL, USA
| | - Pablo Jiménez-Bonilla
- Department of Biosystems Engineering, Auburn University, Auburn, AL, USA.,Center for Bioenergy and Bioproducts, Auburn University, Auburn, AL, USA.,School of Chemistry, National University (UNA), Heredia, Costa Rica
| | - Yanyan Gu
- Department of Biosystems Engineering, Auburn University, Auburn, AL, USA.,Center for Bioenergy and Bioproducts, Auburn University, Auburn, AL, USA
| | - Junping Zhou
- Department of Biosystems Engineering, Auburn University, Auburn, AL, USA.,Center for Bioenergy and Bioproducts, Auburn University, Auburn, AL, USA
| | - Zhong-Tian Zhang
- Department of Biosystems Engineering, Auburn University, Auburn, AL, USA.,Center for Bioenergy and Bioproducts, Auburn University, Auburn, AL, USA
| | - Mingfeng Cao
- Department of Chemical and Biological Engineering, Iowa State University, Ames, IA, USA.,NSF Engineering Research Center for Biorenewable Chemicals, Iowa State University, Ames, IA, USA
| | - Di Jiang
- Department of Applied Chemistry, University of Science and Technology of China, Hefei, China
| | - Shuning Wang
- State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, China
| | - Xian-Wei Liu
- Department of Applied Chemistry, University of Science and Technology of China, Hefei, China
| | - Zengyi Shao
- Department of Chemical and Biological Engineering, Iowa State University, Ames, IA, USA.,NSF Engineering Research Center for Biorenewable Chemicals, Iowa State University, Ames, IA, USA
| | - Ilya Borovok
- The Shmunis School of Biomedicine and Cancer Research, Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv, Israel
| | - Haibo Huang
- Department of Food Science and Technology, Virginia Tech, Blacksburg, VA, USA.
| | - Yi Wang
- Department of Biosystems Engineering, Auburn University, Auburn, AL, USA. .,Center for Bioenergy and Bioproducts, Auburn University, Auburn, AL, USA.
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Pasechnek A, Rabinovich L, Stadnyuk O, Azulay G, Mioduser J, Argov T, Borovok I, Sigal N, Herskovits AA. Active Lysogeny in Listeria Monocytogenes Is a Bacteria-Phage Adaptive Response in the Mammalian Environment. Cell Rep 2021; 32:107956. [PMID: 32726621 PMCID: PMC7397523 DOI: 10.1016/j.celrep.2020.107956] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 05/05/2020] [Accepted: 07/02/2020] [Indexed: 01/20/2023] Open
Abstract
Some Listeria monocytogenes (Lm) strains harbor a prophage within the comK gene, which renders it inactive. During Lm infection of macrophage cells, the prophage turns into a molecular switch, promoting comK gene expression and therefore Lm intracellular growth. During this process, the prophage does not produce infective phages or cause bacterial lysis, suggesting it has acquired an adaptive behavior suited to the pathogenic lifestyle of its host. In this study, we demonstrate that this non-classical phage behavior, named active lysogeny, relies on a transcriptional response that is specific to the intracellular niche. While the prophage undergoes lytic induction, the process is arrested midway, preventing the transcription of the late genes. Further, we demonstrate key phage factors, such as LlgA transcription regulator and a DNA replicase, that support the phage adaptive behavior. This study provides molecular insights into the adaptation of phages to their pathogenic hosts, uncovering unusual cooperative interactions.
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Affiliation(s)
- Anna Pasechnek
- The School of Molecular Cell Biology and Biotechnology, Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel- Aviv 69978, Israel
| | - Lev Rabinovich
- The School of Molecular Cell Biology and Biotechnology, Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel- Aviv 69978, Israel
| | - Olga Stadnyuk
- The School of Molecular Cell Biology and Biotechnology, Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel- Aviv 69978, Israel
| | - Gil Azulay
- The School of Molecular Cell Biology and Biotechnology, Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel- Aviv 69978, Israel
| | - Jessica Mioduser
- The School of Molecular Cell Biology and Biotechnology, Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel- Aviv 69978, Israel
| | - Tal Argov
- The School of Molecular Cell Biology and Biotechnology, Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel- Aviv 69978, Israel
| | - Ilya Borovok
- The School of Molecular Cell Biology and Biotechnology, Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel- Aviv 69978, Israel
| | - Nadejda Sigal
- The School of Molecular Cell Biology and Biotechnology, Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel- Aviv 69978, Israel
| | - Anat A Herskovits
- The School of Molecular Cell Biology and Biotechnology, Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel- Aviv 69978, Israel.
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Feng J, Zong W, Wang P, Zhang ZT, Gu Y, Dougherty M, Borovok I, Wang Y. RRNPP-type quorum-sensing systems regulate solvent formation, sporulation and cell motility in Clostridium saccharoperbutylacetonicum. Biotechnol Biofuels 2020; 13:84. [PMID: 32411297 PMCID: PMC7206700 DOI: 10.1186/s13068-020-01723-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 04/30/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND Clostridium saccharoperbutylacetonicum N1-4 (HMT) is a strictly anaerobic, spore-forming Gram-positive bacterium capable of hyper-butanol production through the well-known acetone-butanol-ethanol fermentation process. Recently, five putative RRNPP-type QSSs (here designated as QSS1 to QSS5) were predicted in this bacterial strain, each of which comprises a putative RRNPP-type regulator (QssR1 to QssR5) and a cognate signaling peptide precursor (QssP1 to QssP5). In addition, both proteins are encoded by the same operon. The functions of these multiple RRNPP-type QSSs are unknown. RESULTS To elucidate the function of multiple RRNPP-type QSSs as related to cell metabolism and solvent production in N1-4 (HMT), we constructed qssR-deficient mutants ΔR1, ΔR2, ΔR3 and ΔR5 through gene deletion using CRISPR-Cas9 and N1-4-dcas9-R4 (with the QssR4 expression suppressed using CRISPR-dCas9). We also constructed complementation strains by overexpressing the corresponding regulator gene. Based on systematic characterization, results indicate that QSS1, QSS2, QSS3, and QSS5 positively regulate the sol operon expression and thus solvent production, but they likely negatively regulate cell motility. Consequently, QSS4 might not directly regulate solvent production, but positively affect cell migration. In addition, QSS3 and QSS5 appear to positively regulate sporulation efficiency. CONCLUSIONS Our study provides the first insights into the roles of multiple RRNPP-type QSSs of C. saccharoperbutylacetonicum for the regulation of solvent production, cell motility, and sporulation. Results of this study expand our knowledge of how multiple paralogous QSSs are involved in the regulation of essential bacterial metabolism pathways.
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Affiliation(s)
- Jun Feng
- Department of Biosystems Engineering, Auburn University, 350 Mell Street, Auburn, AL 36849 USA
| | - Wenming Zong
- Department of Biosystems Engineering, Auburn University, 350 Mell Street, Auburn, AL 36849 USA
- School of Engineering, Anhui Agricultural University, Hefei, 230036 China
| | - Pixiang Wang
- Department of Biosystems Engineering, Auburn University, 350 Mell Street, Auburn, AL 36849 USA
| | - Zhong-Tian Zhang
- Department of Biosystems Engineering, Auburn University, 350 Mell Street, Auburn, AL 36849 USA
| | - Yanyan Gu
- Department of Biosystems Engineering, Auburn University, 350 Mell Street, Auburn, AL 36849 USA
| | - Mark Dougherty
- Department of Biosystems Engineering, Auburn University, 350 Mell Street, Auburn, AL 36849 USA
| | - Ilya Borovok
- School of Molecular Cell Biology and Biotechnology, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, 6997801 Tel Aviv, Israel
| | - Yi Wang
- Department of Biosystems Engineering, Auburn University, 350 Mell Street, Auburn, AL 36849 USA
- Center for Bioenergy and Bioproducts, Auburn University, Auburn, AL 36849 USA
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6
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Yair Y, Borovok I, Mikula I, Falk R, Fox LK, Gophna U, Lysnyansky I. Genomics-based epidemiology of bovine Mycoplasma bovis strains in Israel. BMC Genomics 2020; 21:70. [PMID: 31969124 PMCID: PMC6977290 DOI: 10.1186/s12864-020-6460-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 01/07/2020] [Indexed: 02/08/2023] Open
Abstract
Background Mycoplasma bovis is an important etiologic agent of bovine mycoplasmosis affecting cattle production and animal welfare. In the past in Israel, M. bovis has been most frequently associated with bovine respiratory disease (BRD) and was rarely isolated from mastitis. This situation changed in 2008 when M. bovis-associated mastitis emerged in Israel. The aim of this study was to utilize whole genome sequencing to evaluate the molecular epidemiology and genomic diversity of M. bovis mastitis-associated strains and their genetic relatedness to M. bovis strains isolated from BRD in local feedlot calves and those imported to Israel from different European countries and Australia. Results Phylogeny based on total single nucleotide polymorphism (SNP) analysis of 225 M. bovis genomes clearly showed clustering of isolates on the basis of geographical origin: strains isolated from European countries clustered together and separately from Australian and Chinese isolates, while Israeli isolates were found in the both groups. The dominant genotype was identified among local mastitis-associated M. bovis isolates. This genotype showed a close genomic relatedness to M. bovis strains isolated from calves imported to Israel from Australia, to original Australian M. bovis strains, as well as to strains isolated in China. Conclusions This study represents the first comprehensive high-resolution genome-based epidemiological analysis of M. bovis in Israel and illustrates the possible dissemination of the pathogen across the globe by cattle trade.
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Affiliation(s)
- Yael Yair
- School of Molecular Cell Biology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Ilya Borovok
- School of Molecular Cell Biology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Inna Mikula
- Mycoplasma Unit, Division of Avian Diseases, Kimron Veterinary Institute, POB 12, 50250, Beit Dagan, Israel
| | - Rama Falk
- Israel Dairy Board, Laboratory for Udder Health and Milk Quality, Caesarea, Israel
| | - Larry K Fox
- Washington State University, Pullman, WA, USA
| | - Uri Gophna
- School of Molecular Cell Biology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Inna Lysnyansky
- Mycoplasma Unit, Division of Avian Diseases, Kimron Veterinary Institute, POB 12, 50250, Beit Dagan, Israel.
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7
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Hoffman S, Aviv Cohen N, Carroll IM, Tulchinsky H, Borovok I, Dotan I, Maharshak N. Faecal Proteases from Pouchitis Patients Activate Protease Activating Receptor-2 to Disrupt the Epithelial Barrier. J Crohns Colitis 2019; 13:1558-1568. [PMID: 31056700 DOI: 10.1093/ecco-jcc/jjz086] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
BACKGROUND AND AIMS The pathogenesis of pouch inflammation may involve epithelial barrier disruption. We investigated whether faecal proteolytic activity is increased during pouchitis and results in epithelial barrier dysfunction through protease activating receptor [PAR] activation, and assessed whether the intestinal microbiome may be the source of the proteases. METHODS Faecal samples were measured for protease activity using a fluorescein isothiocyanate [FITC]-casein florescence assay. Caco-2 cell monolayers were exposed to faecal supernatants to assess permeability to FITC-dextran. Tight junction protein integrity and PAR activation were assessed by immunoblot and immunofluorescence. A truncated PAR2 protein in Caco-2 cells was achieved by stable transfection using CRISPR/Cas9 plasmid. PAR2 activation in pouch biopsies was examined using antibodies directed to the N-terminus of the protein. Microbial composition was analysed based on 16S rRNA gene sequence analysis. RESULTS Ten pouchitis patients, six normal pouch [NP] patients and nine healthy controls [HC] were recruited. The pouchitis patients exhibited a 5.19- and 5.35-fold higher faecal protease [FP] activity [p ≤ 0.05] compared to the NP and HC participants, respectively. The genus Haemophilus was positively associated with FP activity [R = 0.718, false discovery rate < 0.1]. Faecal supernatants from pouchitis patients activated PAR2 on Caco-2 monolayers, disrupted tight junction proteins and increased epithelial permeability. PAR2 truncation in Caco-2 abrogated faecal protease-mediated permeability. Pouch biopsies obtained from pouchitis patients, but not from NP patients, displayed PAR2 activation. CONCLUSIONS Protease-producing bacteria may increase faecal proteolytic activity that results in pouch inflammation through disruption of tight junction proteins and increased epithelial permeability in a PAR2-dependent manner. This mechanism may initiate or propagate pouch inflammation.
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Affiliation(s)
- Sarit Hoffman
- The Research Center for Digestive Tract and Liver Diseases, Tel Aviv Medical Center, Tel Aviv, Israel.,Sackler Faculty of Medicine Tel-Aviv University, Tel Aviv, Israel
| | - Nathaniel Aviv Cohen
- The Research Center for Digestive Tract and Liver Diseases, Tel Aviv Medical Center, Tel Aviv, Israel.,IBD Center, Tel Aviv Medical Center, Tel Aviv, Israel.,Department of Gastroenterology and Liver Diseases, Tel Aviv Medical Center, Tel Aviv, Israel.,Sackler Faculty of Medicine Tel-Aviv University, Tel Aviv, Israel
| | - Ian M Carroll
- Center for Gastrointestinal Biology and Disease, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Hagit Tulchinsky
- Division of Surgery Colorectal Unit, Tel Aviv Medical Center, Tel Aviv, Israel.,Sackler Faculty of Medicine Tel-Aviv University, Tel Aviv, Israel
| | - Ilya Borovok
- Department of Molecular and Microbiology and Biotechnology, Tel Aviv University, Tel Aviv, Israel
| | - Iris Dotan
- Division of Gastroenterology, Rabin Medical Center, Petah Tikva, Israel.,Sackler Faculty of Medicine Tel-Aviv University, Tel Aviv, Israel
| | - Nitsan Maharshak
- The Research Center for Digestive Tract and Liver Diseases, Tel Aviv Medical Center, Tel Aviv, Israel.,IBD Center, Tel Aviv Medical Center, Tel Aviv, Israel.,Department of Gastroenterology and Liver Diseases, Tel Aviv Medical Center, Tel Aviv, Israel.,Sackler Faculty of Medicine Tel-Aviv University, Tel Aviv, Israel
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Argov T, Sapir SR, Pasechnek A, Azulay G, Stadnyuk O, Rabinovich L, Sigal N, Borovok I, Herskovits AA. Coordination of cohabiting phage elements supports bacteria-phage cooperation. Nat Commun 2019; 10:5288. [PMID: 31754112 PMCID: PMC6872733 DOI: 10.1038/s41467-019-13296-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 10/30/2019] [Indexed: 01/08/2023] Open
Abstract
Bacterial pathogens often carry multiple prophages and other phage-derived elements within their genome, some of which can produce viral particles in response to stress. Listeria monocytogenes 10403S harbors two phage elements in its chromosome, both of which can trigger bacterial lysis under stress: an active prophage (ϕ10403S) that promotes the virulence of its host and can produce infective virions, and a locus encoding phage tail-like bacteriocins. Here, we show that the two phage elements are co-regulated, with the bacteriocin locus controlling the induction of the prophage and thus its activity as a virulence-associated molecular switch. More specifically, a metalloprotease encoded in the bacteriocin locus is upregulated in response to stress and acts as an anti-repressor for CI-like repressors encoded in each phage element. Our results provide molecular insight into the phenomenon of polylysogeny and its intricate adaptation to complex environments.
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Affiliation(s)
- Tal Argov
- The School of Molecular Cell Biology and Biotechnology, Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv, 69978, Israel
| | - Shai Ran Sapir
- The School of Molecular Cell Biology and Biotechnology, Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv, 69978, Israel
| | - Anna Pasechnek
- The School of Molecular Cell Biology and Biotechnology, Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv, 69978, Israel
| | - Gil Azulay
- The School of Molecular Cell Biology and Biotechnology, Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv, 69978, Israel
| | - Olga Stadnyuk
- The School of Molecular Cell Biology and Biotechnology, Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv, 69978, Israel
| | - Lev Rabinovich
- The School of Molecular Cell Biology and Biotechnology, Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv, 69978, Israel
| | - Nadejda Sigal
- The School of Molecular Cell Biology and Biotechnology, Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv, 69978, Israel
| | - Ilya Borovok
- The School of Molecular Cell Biology and Biotechnology, Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv, 69978, Israel
| | - Anat A Herskovits
- The School of Molecular Cell Biology and Biotechnology, Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv, 69978, Israel.
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9
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Grinberg IR, Yaniv O, de Ora LO, Muñoz-Gutiérrez I, Hershko A, Livnah O, Bayer EA, Borovok I, Frolow F, Lamed R, Voronov-Goldman M. Distinctive ligand-binding specificities of tandem PA14 biomass-sensory elements from Clostridium thermocellum and Clostridium clariflavum. Proteins 2019; 87:917-930. [PMID: 31162722 PMCID: PMC6852018 DOI: 10.1002/prot.25753] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2019] [Revised: 05/26/2019] [Accepted: 05/30/2019] [Indexed: 11/25/2022]
Abstract
Cellulolytic clostridia use a highly efficient cellulosome system to degrade polysaccharides. To regulate genes encoding enzymes of the multi‐enzyme cellulosome complex, certain clostridia contain alternative sigma I (σI) factors that have cognate membrane‐associated anti‐σI factors (RsgIs) which act as polysaccharide sensors. In this work, we analyzed the structure‐function relationship of the extracellular sensory elements of Clostridium (Ruminiclostridium) thermocellum and Clostridium clariflavum (RsgI3 and RsgI4, respectively). These elements were selected for comparison, as each comprised two tandem PA14‐superfamily motifs. The X‐ray structures of the PA14 modular dyads from the two bacterial species were determined, both of which showed a high degree of structural and sequence similarity, although their binding preferences differed. Bioinformatic approaches indicated that the DNA sequence of promoter of sigI/rsgI operons represents a strong signature, which helps to differentiate binding specificity of the structurally similar modules. The σI4‐dependent C. clariflavum promoter sequence correlates with binding of RsgI4_PA14 to xylan and was identified in genes encoding xylanases, whereas the σI3‐dependent C. thermocellum promoter sequence correlates with RsgI3_PA14 binding to pectin and regulates pectin degradation‐related genes. Structural similarity between clostridial PA14 dyads to PA14‐containing proteins in yeast helped identify another crucial signature element: the calcium‐binding loop 2 (CBL2), which governs binding specificity. Variations in the five amino acids that constitute this loop distinguish the pectin vs xylan specificities. We propose that the first module (PA14A) is dominant in directing the binding to the ligand in both bacteria. The two X‐ray structures of the different PA14 dyads represent the first reported structures of tandem PA14 modules.
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Affiliation(s)
- Inna Rozman Grinberg
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv, Israel.,Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Oren Yaniv
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv, Israel
| | - Lizett Ortiz de Ora
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv, Israel.,Department of Chemistry, University of California, Irvine, California
| | - Iván Muñoz-Gutiérrez
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, Israel.,Outreach Research Training and Minority Science Programs, School of Biological Sciences, University of California, Irvine, California
| | - Almog Hershko
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv, Israel
| | - Oded Livnah
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, The Wolfson Centre for Applied Structural Biology, The Hebrew University of Jerusalem, The Edmond J. Safra Campus, Jerusalem, Israel
| | - Edward A Bayer
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, Israel
| | - Ilya Borovok
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv, Israel
| | - Felix Frolow
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv, Israel
| | - Raphael Lamed
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv, Israel
| | - Milana Voronov-Goldman
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv, Israel
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10
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Rozman Grinberg I, Lundin D, Hasan M, Crona M, Jonna VR, Loderer C, Sahlin M, Markova N, Borovok I, Berggren G, Hofer A, Logan DT, Sjöberg BM. Novel ATP-cone-driven allosteric regulation of ribonucleotide reductase via the radical-generating subunit. eLife 2018; 7:31529. [PMID: 29388911 PMCID: PMC5794259 DOI: 10.7554/elife.31529] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2017] [Accepted: 12/23/2017] [Indexed: 12/27/2022] Open
Abstract
Ribonucleotide reductases (RNRs) are key enzymes in DNA metabolism, with allosteric mechanisms controlling substrate specificity and overall activity. In RNRs, the activity master-switch, the ATP-cone, has been found exclusively in the catalytic subunit. In two class I RNR subclasses whose catalytic subunit lacks the ATP-cone, we discovered ATP-cones in the radical-generating subunit. The ATP-cone in the Leeuwenhoekiella blandensis radical-generating subunit regulates activity via quaternary structure induced by binding of nucleotides. ATP induces enzymatically competent dimers, whereas dATP induces non-productive tetramers, resulting in different holoenzymes. The tetramer forms by interactions between ATP-cones, shown by a 2.45 Å crystal structure. We also present evidence for an MnIIIMnIV metal center. In summary, lack of an ATP-cone domain in the catalytic subunit was compensated by transfer of the domain to the radical-generating subunit. To our knowledge, this represents the first observation of transfer of an allosteric domain between components of the same enzyme complex. When a cell copies its DNA, it uses four different building blocks called deoxyribonucleotides (dNTPs). These consist of one of the four ‘bases’ (A, T, C and G), which pair up to link the two strands of DNA in the double helix, bound to a sugar and a phosphate group. If the cell contains too little or too much of one of these building blocks, an incorrect base may be inserted into the DNA. This results in a mutation, which in bacteria can cause death, and in animals may lead to cancer. The enzyme that fabricates and carefully controls the amount of each dNTP building block inside a cell is called ribonucleotide reductase. Once there are enough building blocks in a cell the enzyme is turned off. A part of the enzyme called the ATP-cone acts as an on/off switch to control this activity. The ribonucleotide reductase consists of a large component and a small component. Until now, studies of the ATP-cone have found it only in the large component of the enzyme. However, when looking through a public database of sequence data, Rozman Grinberg et al. noticed that ribonucleotide reductases in some bacteria have their ATP-cone joined to the small component. Does this ATP-cone also control the amounts of dNTP building blocks inside cells and, if so, how? Rozman Grinberg et al. studied one such ATP-cone in a ribonucleotide reductase from a bacterium (named Leeuwenhoekiella blandensis) found in the Mediterranean Sea. This revealed that when the amount of dNTP building blocks reaches a certain limit, the ATP-cone turns off the enzyme. Examining the three-dimensional structure of the enzyme using a technique called X-ray crystallography revealed that when turned off, the enzyme’s small components are glued together in pairs. This prevents them from working. Rozman Grinberg et al. also discovered that this enzyme contains a new type of metal center with two manganese ions suggesting that a new reaction mechanism may operate in this class of ribonucleotide reductase. These findings support a theory that biological on/off switches can evolve rapidly. In addition to its evolutionary and biomedical interest, understanding how the ATP-cone works might help to improve the enzymes used in industrial processes.
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Affiliation(s)
- Inna Rozman Grinberg
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Daniel Lundin
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Mahmudul Hasan
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden.,Department of Biochemistry and Structural Biology, Lund University, Lund, Sweden
| | | | | | - Christoph Loderer
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Margareta Sahlin
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | | | - Ilya Borovok
- Department of Molecular Microbiology and Biotechnology, Tel-Aviv University, Tel Aviv-Yafo, Israel
| | - Gustav Berggren
- Department of Chemistry, Uppsala University, Uppsala, Sweden
| | - Anders Hofer
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, Sweden
| | - Derek T Logan
- Department of Biochemistry and Structural Biology, Lund University, Lund, Sweden
| | - Britt-Marie Sjöberg
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
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11
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Yoav S, Barak Y, Shamshoum M, Borovok I, Lamed R, Dassa B, Hadar Y, Morag E, Bayer EA. How does cellulosome composition influence deconstruction of lignocellulosic substrates in Clostridium ( Ruminiclostridium) thermocellum DSM 1313? Biotechnol Biofuels 2017; 10:222. [PMID: 28932263 PMCID: PMC5604425 DOI: 10.1186/s13068-017-0909-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Accepted: 09/07/2017] [Indexed: 05/23/2023]
Abstract
BACKGROUND Bioethanol production processes involve enzymatic hydrolysis of pretreated lignocellulosic biomass into fermentable sugars. Due to the relatively high cost of enzyme production, the development of potent and cost-effective cellulolytic cocktails is critical for increasing the cost-effectiveness of bioethanol production. In this context, the multi-protein cellulolytic complex of Clostridium (Ruminiclostridium) thermocellum, the cellulosome, was studied here. C. thermocellum is known to assemble cellulosomes of various subunit (enzyme) compositions, in response to the available carbon source. In the current study, different carbon sources were used, and their influence on both cellulosomal composition and the resultant activity was investigated. RESULTS Glucose, cellobiose, microcrystalline cellulose, alkaline-pretreated switchgrass, alkaline-pretreated corn stover, and dilute acid-pretreated corn stover were used as sole carbon sources in the growth media of C. thermocellum strain DSM 1313. The purified cellulosomes were compared for their activity on selected cellulosic substrates. Interestingly, cellulosomes derived from cells grown on lignocellulosic biomass showed no advantage in hydrolyzing the original carbon source used for their production. Instead, microcrystalline cellulose- and glucose-derived cellulosomes were equal or superior in their capacity to deconstruct lignocellulosic biomass. Mass spectrometry analysis revealed differential composition of catalytic and structural subunits (scaffoldins) in the different cellulosome samples. The most abundant catalytic subunits in all cellulosome types include Cel48S, Cel9K, Cel9Q, Cel9R, and Cel5G. Microcrystalline cellulose- and glucose-derived cellulosome samples showed higher endoglucanase-to-exoglucanase ratios and higher catalytic subunit-per-scaffoldin ratios compared to lignocellulose-derived cellulosome types. CONCLUSION The results reported here highlight the finding that cellulosomes derived from cells grown on glucose and microcrystalline cellulose are more efficient in their action on cellulosic substrates than other cellulosome preparations. These results should be considered in the future development of C. thermocellum-based cellulolytic cocktails, designer cellulosomes, or engineering of improved strains for deconstruction of lignocellulosic biomass.
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Affiliation(s)
- Shahar Yoav
- Department of Plant Pathology and Microbiology, Robert H. Smith Faculty of Agriculture, Food and Environment, The Advanced School for Environmental Studies, The Hebrew University of Jerusalem, 76100 Rehovot, Israel
- Designer Energy Ltd, 2 Bergman Street, Rehovot, Israel
| | - Yoav Barak
- Bio-Nano Unit, Chemical Research Support, The Weizmann Institute of Science, 761000 Rehovot, Israel
| | - Melina Shamshoum
- Department of Biomolecular Sciences, The Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Ilya Borovok
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv, Israel
| | - Raphael Lamed
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv, Israel
| | - Bareket Dassa
- Department of Biomolecular Sciences, The Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Yitzhak Hadar
- Department of Plant Pathology and Microbiology, Robert H. Smith Faculty of Agriculture, Food and Environment, The Advanced School for Environmental Studies, The Hebrew University of Jerusalem, 76100 Rehovot, Israel
| | - Ely Morag
- Department of Biomolecular Sciences, The Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Edward A. Bayer
- Department of Biomolecular Sciences, The Weizmann Institute of Science, 76100 Rehovot, Israel
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12
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Argov T, Azulay G, Pasechnek A, Stadnyuk O, Ran-Sapir S, Borovok I, Sigal N, Herskovits AA. Temperate bacteriophages as regulators of host behavior. Curr Opin Microbiol 2017; 38:81-87. [PMID: 28544996 DOI: 10.1016/j.mib.2017.05.002] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 05/04/2017] [Accepted: 05/08/2017] [Indexed: 12/29/2022]
Abstract
Bacteriophages are ubiquitous and affect most facets of life, from evolution of bacteria, through ecology and global biochemical cycling to human health. The interactions between phages and bacteria often lead to biological novelty and an important milestone in this process is the ability of phages to regulate their host's behavior. In this review article, we will focus on newly reported cases that demonstrate how temperate phages regulate bacterial gene expression and behavior in a variety of bacterial species, pathogenic and environmental. This regulation is mediated by diverse mechanisms such as transcription factors, sRNAs, DNA rearrangements, and even controlled bacterial lysis. The outcome is mutualistic relationships that enable adaptively enhanced communal phage-host fitness under specific conditions.
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Affiliation(s)
- Tal Argov
- Department of Molecular Microbiology and Biotechnology, Faculty of Life Sciences, Tel Aviv University, Tel-Aviv 69978, Israel
| | - Gil Azulay
- Department of Molecular Microbiology and Biotechnology, Faculty of Life Sciences, Tel Aviv University, Tel-Aviv 69978, Israel
| | - Anna Pasechnek
- Department of Molecular Microbiology and Biotechnology, Faculty of Life Sciences, Tel Aviv University, Tel-Aviv 69978, Israel
| | - Olga Stadnyuk
- Department of Molecular Microbiology and Biotechnology, Faculty of Life Sciences, Tel Aviv University, Tel-Aviv 69978, Israel
| | - Shai Ran-Sapir
- Department of Molecular Microbiology and Biotechnology, Faculty of Life Sciences, Tel Aviv University, Tel-Aviv 69978, Israel
| | - Ilya Borovok
- Department of Molecular Microbiology and Biotechnology, Faculty of Life Sciences, Tel Aviv University, Tel-Aviv 69978, Israel
| | - Nadejda Sigal
- Department of Molecular Microbiology and Biotechnology, Faculty of Life Sciences, Tel Aviv University, Tel-Aviv 69978, Israel
| | - Anat A Herskovits
- Department of Molecular Microbiology and Biotechnology, Faculty of Life Sciences, Tel Aviv University, Tel-Aviv 69978, Israel.
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13
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Israeli-Ruimy V, Bule P, Jindou S, Dassa B, Moraïs S, Borovok I, Barak Y, Slutzki M, Hamberg Y, Cardoso V, Alves VD, Najmudin S, White BA, Flint HJ, Gilbert HJ, Lamed R, Fontes CMGA, Bayer EA. Complexity of the Ruminococcus flavefaciens FD-1 cellulosome reflects an expansion of family-related protein-protein interactions. Sci Rep 2017; 7:42355. [PMID: 28186207 PMCID: PMC5301203 DOI: 10.1038/srep42355] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 01/08/2017] [Indexed: 11/25/2022] Open
Abstract
Protein-protein interactions play a vital role in cellular processes as exemplified by assembly of the intricate multi-enzyme cellulosome complex. Cellulosomes are assembled by selective high-affinity binding of enzyme-borne dockerin modules to repeated cohesin modules of structural proteins termed scaffoldins. Recent sequencing of the fiber-degrading Ruminococcus flavefaciens FD-1 genome revealed a particularly elaborate cellulosome system. In total, 223 dockerin-bearing ORFs potentially involved in cellulosome assembly and a variety of multi-modular scaffoldins were identified, and the dockerins were classified into six major groups. Here, extensive screening employing three complementary medium- to high-throughput platforms was used to characterize the different cohesin-dockerin specificities. The platforms included (i) cellulose-coated microarray assay, (ii) enzyme-linked immunosorbent assay (ELISA) and (iii) in-vivo co-expression and screening in Escherichia coli. The data revealed a collection of unique cohesin-dockerin interactions and support the functional relevance of dockerin classification into groups. In contrast to observations reported previously, a dual-binding mode is involved in cellulosome cell-surface attachment, whereas single-binding interactions operate for cellulosome integration of enzymes. This sui generis cellulosome model enhances our understanding of the mechanisms governing the remarkable ability of R. flavefaciens to degrade carbohydrates in the bovine rumen and provides a basis for constructing efficient nano-machines applied to biological processes.
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Affiliation(s)
- Vered Israeli-Ruimy
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, Israel
| | - Pedro Bule
- CIISA – Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
| | - Sadanari Jindou
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv, Israel
| | - Bareket Dassa
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, Israel
| | - Sarah Moraïs
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, Israel
| | - Ilya Borovok
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv, Israel
| | - Yoav Barak
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, Israel
- Chemical Research Support, The Weizmann Institute of Science, Rehovot, Israel
| | - Michal Slutzki
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, Israel
| | - Yuval Hamberg
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, Israel
| | - Vânia Cardoso
- CIISA – Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
| | - Victor D. Alves
- CIISA – Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
| | - Shabir Najmudin
- CIISA – Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
| | - Bryan A. White
- Department of Animal Sciences, Institute for Genomic Biology, University of Illinois at Urbana–Champaign, Champaign, IL, USA
- Department of Animal Sciences, University of Illinois at Urbana–Champaign, Champaign, IL, USA
| | - Harry J. Flint
- Microbiology Group, Rowett Institute of Nutrition and Health, University of Aberdeen, Foresterhill, Aberdeen, Scotland, UK
| | - Harry J. Gilbert
- Institute for Cell and Molecular Biosciences, Newcastle University, The Medical School, Newcastle upon Tyne NE2 4HH, UK
| | - Raphael Lamed
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv, Israel
| | - Carlos M. G. A. Fontes
- CIISA – Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
| | - Edward A. Bayer
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, Israel
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14
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Feiner R, Argov T, Rabinovich L, Sigal N, Borovok I, Herskovits AA. A new perspective on lysogeny: prophages as active regulatory switches of bacteria. Nat Rev Microbiol 2016; 13:641-50. [PMID: 26373372 DOI: 10.1038/nrmicro3527] [Citation(s) in RCA: 269] [Impact Index Per Article: 33.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Unlike lytic phages, temperate phages that enter lysogeny maintain a long-term association with their bacterial host. In this context, mutually beneficial interactions can evolve that support efficient reproduction of both phages and bacteria. Temperate phages are integrated into the bacterial chromosome as large DNA insertions that can disrupt gene expression, and they may pose a fitness burden on the cell. However, they have also been shown to benefit their bacterial hosts by providing new functions in a bacterium-phage symbiotic interaction termed lysogenic conversion. In this Opinion article, we discuss another type of bacterium-phage interaction, active lysogeny, in which phages or phage-like elements are integrated into the bacterial chromosome within critical genes or operons and serve as switches that regulate bacterial genes via genome excision.
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Affiliation(s)
- Ron Feiner
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv 69978, Israel
| | - Tal Argov
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv 69978, Israel
| | - Lev Rabinovich
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv 69978, Israel
| | - Nadejda Sigal
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv 69978, Israel
| | - Ilya Borovok
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv 69978, Israel
| | - Anat A Herskovits
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv 69978, Israel
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15
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Ben David Y, Dassa B, Borovok I, Lamed R, Koropatkin NM, Martens EC, White BA, Bernalier-Donadille A, Duncan SH, Flint HJ, Bayer EA, Moraïs S. Ruminococcal cellulosome systems from rumen to human. Environ Microbiol 2015; 17:3407-26. [PMID: 25845888 DOI: 10.1111/1462-2920.12868] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Revised: 03/24/2015] [Accepted: 03/31/2015] [Indexed: 01/19/2023]
Abstract
A cellulolytic fiber-degrading bacterium, Ruminococcus champanellensis, was isolated from human faecal samples, and its genome was recently sequenced. Bioinformatic analysis of the R. champanellensis genome revealed numerous cohesin and dockerin modules, the basic elements of the cellulosome, and manual sequencing of partially sequenced genomic segments revealed two large tandem scaffoldin-coding genes that form part of a gene cluster. Representative R. champanellensis dockerins were tested against putative cohesins, and the results revealed three different cohesin-dockerin binding profiles which implied two major types of cellulosome architectures: (i) an intricate cell-bound system and (ii) a simplistic cell-free system composed of a single cohesin-containing scaffoldin. The cell-bound system can adopt various enzymatic architectures, ranging from a single enzyme to a large enzymatic complex comprising up to 11 enzymes. The variety of cellulosomal components together with adaptor proteins may infer a very tight regulation of its components. The cellulosome system of the human gut bacterium R. champanellensis closely resembles that of the bovine rumen bacterium Ruminococcus flavefaciens. The two species contain orthologous gene clusters comprising fundamental components of cellulosome architecture. Since R. champanellensis is the only human colonic bacterium known to degrade crystalline cellulose, it may thus represent a keystone species in the human gut.
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Affiliation(s)
- Yonit Ben David
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, Israel
| | - Bareket Dassa
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, Israel
| | - Ilya Borovok
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv, Israel
| | - Raphael Lamed
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv, Israel
| | - Nicole M Koropatkin
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - Eric C Martens
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - Bryan A White
- Department of Animal Sciences and Institute for Genomic Biology, University of Illinois, Urbana, IL, USA
| | | | - Sylvia H Duncan
- Microbiology Group, Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, UK
| | - Harry J Flint
- Microbiology Group, Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, UK
| | - Edward A Bayer
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, Israel
| | - Sarah Moraïs
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, Israel
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16
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Sand A, Holwerda EK, Ruppertsberger NM, Maloney M, Olson DG, Nataf Y, Borovok I, Sonenshein AL, Bayer EA, Lamed R, Lynd LR, Shoham Y. Three cellulosomal xylanase genes inClostridium thermocellumare regulated by both vegetative SigA (σA) and alternative SigI6 (σI6) factors. FEBS Lett 2015; 589:3133-40. [DOI: 10.1016/j.febslet.2015.08.026] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2015] [Revised: 08/10/2015] [Accepted: 08/14/2015] [Indexed: 11/29/2022]
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17
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Voronov-Goldman M, Yaniv O, Gul O, Yoffe H, Salama-Alber O, Slutzki M, Levy-Assaraf M, Jindou S, Shimon LJW, Borovok I, Bayer EA, Lamed R, Frolow F. Standalone cohesin as a molecular shuttle in cellulosome assembly. FEBS Lett 2015; 589:1569-76. [PMID: 25896019 DOI: 10.1016/j.febslet.2015.04.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Revised: 04/06/2015] [Accepted: 04/08/2015] [Indexed: 11/20/2022]
Abstract
The cellulolytic bacterium Ruminococcus flavefaciens of the herbivore rumen produces an elaborate cellulosome system, anchored to the bacterial cell wall via the covalently bound scaffoldin ScaE. Dockerin-bearing scaffoldins also bind to an autonomous cohesin of unknown function, called cohesin G (CohG). Here, we demonstrate that CohG binds to the scaffoldin-borne dockerin in opposite orientation on a distinct site, relative to that of ScaE. Based on these structural data, we propose that the complexed dockerin is still available to bind ScaE on the cell surface. CohG may thus serve as a molecular shuttle for delivery of scaffoldins to the bacterial cell surface.
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Affiliation(s)
- Milana Voronov-Goldman
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, 69978, Israel; The Daniella Rich Institute for Structural Biology, Tel Aviv University, 69978, Israel
| | - Oren Yaniv
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, 69978, Israel; The Daniella Rich Institute for Structural Biology, Tel Aviv University, 69978, Israel
| | - Ozgur Gul
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Hagar Yoffe
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, 69978, Israel; The Daniella Rich Institute for Structural Biology, Tel Aviv University, 69978, Israel
| | - Orly Salama-Alber
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Michal Slutzki
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Maly Levy-Assaraf
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, 69978, Israel; The Daniella Rich Institute for Structural Biology, Tel Aviv University, 69978, Israel
| | - Sadanari Jindou
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, 69978, Israel; Faculty of Agriculture, Meijo University, Nagoya 468-8502, Japan
| | - Linda J W Shimon
- Department of Chemical Research Support, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Ilya Borovok
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, 69978, Israel
| | - Edward A Bayer
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel.
| | - Raphael Lamed
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, 69978, Israel; The Daniella Rich Institute for Structural Biology, Tel Aviv University, 69978, Israel.
| | - Felix Frolow
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, 69978, Israel; The Daniella Rich Institute for Structural Biology, Tel Aviv University, 69978, Israel
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18
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Lobel L, Sigal N, Borovok I, Belitsky BR, Sonenshein AL, Herskovits AA. The metabolic regulator CodY links Listeria monocytogenes metabolism to virulence by directly activating the virulence regulatory gene prfA. Mol Microbiol 2014; 95:624-44. [PMID: 25430920 DOI: 10.1111/mmi.12890] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/23/2014] [Indexed: 11/30/2022]
Abstract
Metabolic adaptations are critical to the ability of bacterial pathogens to grow within host cells and are normally preceded by sensing of host-specific metabolic signals, which in turn can influence the pathogen's virulence state. Previously, we reported that the intracellular bacterial pathogen Listeria monocytogenes responds to low availability of branched-chain amino acids (BCAAs) within mammalian cells by up-regulating both BCAA biosynthesis and virulence genes. The induction of virulence genes required the BCAA-responsive transcription regulator, CodY, but the molecular mechanism governing this mode of regulation was unclear. In this report, we demonstrate that CodY directly binds the coding sequence of the L. monocytogenes master virulence activator gene, prfA, 15 nt downstream of its start codon, and that this binding results in up-regulation of prfA transcription specifically under low concentrations of BCAA. Mutating this site abolished CodY binding and reduced prfA transcription in macrophages, and attenuated bacterial virulence in mice. Notably, the mutated binding site did not alter prfA transcription or PrfA activity under other conditions that are known to activate PrfA, such as during growth in the presence of glucose-1-phosphate. This study highlights the tight crosstalk between L. monocytogenes metabolism and virulence, while revealing novel features of CodY-mediated regulation.
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Affiliation(s)
- Lior Lobel
- The Department of Molecular Microbiology and Biotechnology, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, 69978, Israel
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Rozman Grinberg I, Yin G, Borovok I, Berg Miller ME, Yeoman CJ, Dassa B, Yu Z, Mizrahi I, Flint HJ, Bayer EA, White BA, Lamed R. Functional phylotyping approach for assessing intraspecific diversity of Ruminococcus albus within the rumen microbiome. FEMS Microbiol Lett 2014; 362:1-10. [PMID: 25673657 DOI: 10.1093/femsle/fnu047] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Ruminococcus albus, a cellulolytic bacterium, is a critical member of the rumen community. Ruminococcus albus lacks a classical cellulosome complex, but it possesses a unique family 37 carbohydrate-binding module (CBM37), which is integrated into a variety of carbohydrate-active enzymes. We developed a potential molecular tool for functional phylotyping of the R. albus population in the rumen, based on a variable region in the cel48A gene. cel48A encodes a single copy of the CBM37-associated family 48 glycoside hydrolase in all known strains of this bacterium. A segment of the cel48A gene was amplified from rumen metagenomic samples of four bovines, and its abundance and diversity were evaluated. Analysis of the obtained sequences revealed the co-existence of multiple functional phylotypes of cel48A in all four animals. These included sequences identical or similar to those of R. albus isolates (reference strains), as well as several novel sequences. The dominant cel48A type varied among animals. This method can be used for detection of intraspecific diversity of R. albus in metagenomic samples. Together with scaC, a previously reported gene marker for R. flavefaciens, we present a set of two species-specific markers for phylotyping of Ruminococci in the herbivore rumen.
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Affiliation(s)
- Inna Rozman Grinberg
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv 69978, Israel
| | - Guohua Yin
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv 69978, Israel
| | - Ilya Borovok
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv 69978, Israel
| | | | - Carl J Yeoman
- Department of Animal and Range Sciences, Montana State University, Bozeman, MT 59717, USA
| | - Bareket Dassa
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Zhongtang Yu
- The MAPLE Research Initiative, Department of Animal Sciences, The Ohio State University, Columbus, OH 43210, USA
| | - Itzhak Mizrahi
- Department of Ruminant Science, Institute of Animal Sciences, Agricultural Research Organization, Bet Dagan 50250, Israel
| | - Harry J Flint
- Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen AB21 9SB, UK
| | - Edward A Bayer
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Bryan A White
- Institute for Genomic Biology, University of Illinois, Urbana, IL 61801, USA
| | - Raphael Lamed
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv 69978, Israel
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Artzi L, Dassa B, Borovok I, Shamshoum M, Lamed R, Bayer EA. Cellulosomics of the cellulolytic thermophile Clostridium clariflavum. Biotechnol Biofuels 2014; 7:100. [PMID: 26413154 PMCID: PMC4582956 DOI: 10.1186/1754-6834-7-100] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 06/12/2014] [Indexed: 05/23/2023]
Abstract
BACKGROUND Clostridium clariflavum is an anaerobic, thermophilic, Gram-positive bacterium, capable of growth on crystalline cellulose as a single carbon source. The genome of C. clariflavum has been sequenced to completion, and numerous cellulosomal genes were identified, including putative scaffoldin and enzyme subunits. RESULTS Bioinformatic analysis of the C. clariflavum genome revealed 49 cohesin modules distributed on 13 different scaffoldins and 79 dockerin-containing proteins, suggesting an abundance of putative cellulosome assemblies. The 13-scaffoldin system of C. clariflavum is highly reminiscent of the proposed cellulosome system of Acetivibrio cellulolyticus. Analysis of the C. clariflavum type I dockerin sequences indicated a very high level of conservation, wherein the putative recognition residues are remarkably similar to those of A. cellulolyticus. The numerous interactions among the cellulosomal components were elucidated using a standardized affinity ELISA-based fusion-protein system. The results revealed a rather simplistic recognition pattern of cohesin-dockerin interaction, whereby the type I and type II cohesins generally recognized the dockerins of the same type. The anticipated exception to this rule was the type I dockerin of the ScaB adaptor scaffoldin which bound selectively to the type I cohesins of ScaC and ScaJ. CONCLUSIONS The findings reveal an intricate picture of predicted cellulosome assemblies in C. clariflavum. The network of cohesin-dockerin pairs provides a thermophilic alternative to those of C. thermocellum and a basis for subsequent utilization of the C. clariflavum cellulosomal system for biotechnological application.
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Affiliation(s)
- Lior Artzi
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, Israel
| | - Bareket Dassa
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, Israel
| | - Ilya Borovok
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv, Israel
| | - Melina Shamshoum
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, Israel
| | - Raphael Lamed
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv, Israel
| | - Edward A Bayer
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, Israel
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Voronov-Goldman M, Levy-Assaraf M, Yaniv O, Wisserman G, Jindou S, Borovok I, Bayer EA, Lamed R, Shimon LJW, Frolow F. Structural characterization of a novel autonomous cohesin from Ruminococcus flavefaciens. Acta Crystallogr F Struct Biol Commun 2014; 70:450-6. [PMID: 24699736 PMCID: PMC3976060 DOI: 10.1107/s2053230x14004051] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Accepted: 02/20/2014] [Indexed: 11/11/2022] Open
Abstract
Ruminococcus flavefaciens is a cellulolytic bacterium found in the rumen of herbivores and produces one of the most elaborate and variable cellulosome systems. The structure of an R. flavefaciens protein (RfCohG, ZP_06142108), representing a freestanding (non-cellulosomal) type III cohesin module, has been determined. A selenomethionine derivative with a C-terminal histidine tag was crystallized and diffraction data were measured to 2.44 Å resolution. Its structure was determined by single-wavelength anomalous dispersion, revealing eight molecules in the asymmetric unit. RfCohG exhibits the most complex among all known cohesin structures, possessing four α-helical elements and a topographical protuberance on the putative dockerin-binding surface.
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Affiliation(s)
- Milana Voronov-Goldman
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv 69978, Israel
- The Daniella Rich Institute for Structural Biology, Tel Aviv University, Tel Aviv 69978, Israel
| | - Maly Levy-Assaraf
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv 69978, Israel
- The Daniella Rich Institute for Structural Biology, Tel Aviv University, Tel Aviv 69978, Israel
| | - Oren Yaniv
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv 69978, Israel
- The Daniella Rich Institute for Structural Biology, Tel Aviv University, Tel Aviv 69978, Israel
| | - Gloria Wisserman
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv 69978, Israel
| | - Sadanari Jindou
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv 69978, Israel
- Faculty of Agriculture, Meijo University, Nagoya 468-8502, Japan
| | - Ilya Borovok
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv 69978, Israel
| | - Edward A. Bayer
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Raphael Lamed
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv 69978, Israel
- The Daniella Rich Institute for Structural Biology, Tel Aviv University, Tel Aviv 69978, Israel
| | - Linda J. W. Shimon
- Department of Chemical Research Support, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Felix Frolow
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv 69978, Israel
- The Daniella Rich Institute for Structural Biology, Tel Aviv University, Tel Aviv 69978, Israel
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Yaniv O, Fichman G, Borovok I, Shoham Y, Bayer EA, Lamed R, Shimon LJW, Frolow F. Fine-structural variance of family 3 carbohydrate-binding modules as extracellular biomass-sensing components of Clostridium thermocellum anti-σI factors. ACTA ACUST UNITED AC 2014; 70:522-34. [PMID: 24531486 DOI: 10.1107/s139900471302926x] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Accepted: 10/23/2013] [Indexed: 11/11/2022]
Abstract
The anaerobic, thermophilic, cellulosome-producing bacterium Clostridium thermocellum relies on a variety of carbohydrate-active enzymes in order to efficiently break down complex carbohydrates into utilizable simple sugars. The regulation mechanism of the cellulosomal genes was unknown until recently, when genomic analysis revealed a set of putative operons in C. thermocellum that encode σI factors (i.e. alternative σ factors that control specialized regulon activation) and their cognate anti-σI factor (RsgI). These putative anti-σI-factor proteins have modules that are believed to be carbohydrate sensors. Three of these modules were crystallized and their three-dimensional structures were solved. The structures show a high overall degree of sequence and structural similarity to the cellulosomal family 3 carbohydrate-binding modules (CBM3s). The structures of the three carbohydrate sensors (RsgI-CBM3s) and a reference CBM3 are compared in the context of the structural determinants for the specificity of cellulose and complex carbohydrate binding. Fine structural variations among the RsgI-CBM3s appear to result in alternative substrate preferences for each of the sensors.
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Affiliation(s)
- Oren Yaniv
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, 69978 Tel Aviv, Israel
| | - Galit Fichman
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, 69978 Tel Aviv, Israel
| | - Ilya Borovok
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, 69978 Tel Aviv, Israel
| | - Yuval Shoham
- Department of Biotechnology and Food Engineering, Technion - Israel Institute of Technology, Haifa, Israel
| | - Edward A Bayer
- Department of Biological Chemistry, The Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Raphael Lamed
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, 69978 Tel Aviv, Israel
| | - Linda J W Shimon
- Department of Chemical Research Support, The Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Felix Frolow
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, 69978 Tel Aviv, Israel
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23
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Yaniv O, Morag E, Borovok I, Bayer EA, Lamed R, Frolow F, Shimon LJW. Structure of a family 3a carbohydrate-binding module from the cellulosomal scaffoldin CipA of Clostridium thermocellum with flanking linkers: implications for cellulosome structure. Acta Crystallogr Sect F Struct Biol Cryst Commun 2013; 69:733-7. [PMID: 23832198 PMCID: PMC3702315 DOI: 10.1107/s174430911301614x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Accepted: 06/10/2013] [Indexed: 11/10/2022]
Abstract
The cellulosome of the cellulolytic bacterium Clostridium thermocellum has a structural multi-modular protein called CipA (cellulosome-integrating protein A) that includes nine enzyme-binding cohesin modules and a family 3 cellulose-binding module (CBM3a). In the CipA protein, the CBM3a module is located between the second and third cohesin modules and is connected to them via proline/threonine-rich linkers. The structure of CBM3a with portions of the C- and N-terminal flanking linker regions, CBM3a-L, has been determined to a resolution of 1.98 Å. The structure is a β-sandwich with a structural Ca(2+) ion. The structure is consistent with the previously determined CipA CBM structure; however, the structured linker regions provide a deeper insight into the overall cellulosome structure and assembly.
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Affiliation(s)
- Oren Yaniv
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, 69978 Tel Aviv, Israel
- The Daniella Rich Institute for Structural Biology, Tel Aviv University, 69978 Tel Aviv, Israel
| | - Ely Morag
- Department of Biological Chemistry, The Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Ilya Borovok
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, 69978 Tel Aviv, Israel
- The Daniella Rich Institute for Structural Biology, Tel Aviv University, 69978 Tel Aviv, Israel
| | - Edward A. Bayer
- Department of Biological Chemistry, The Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Raphael Lamed
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, 69978 Tel Aviv, Israel
- The Daniella Rich Institute for Structural Biology, Tel Aviv University, 69978 Tel Aviv, Israel
| | - Felix Frolow
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, 69978 Tel Aviv, Israel
- The Daniella Rich Institute for Structural Biology, Tel Aviv University, 69978 Tel Aviv, Israel
| | - Linda J. W. Shimon
- Department of Chemical Research Support, The Weizmann Institute of Science, 76100 Rehovot, Israel
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Xu C, Huang R, Teng L, Wang D, Hemme CL, Borovok I, He Q, Lamed R, Bayer EA, Zhou J, Xu J. Structure and regulation of the cellulose degradome in Clostridium cellulolyticum. Biotechnol Biofuels 2013; 6:73. [PMID: 23657055 PMCID: PMC3656788 DOI: 10.1186/1754-6834-6-73] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2013] [Accepted: 05/01/2013] [Indexed: 05/20/2023]
Abstract
BACKGROUND Many bacteria efficiently degrade lignocellulose yet the underpinning genome-wide metabolic and regulatory networks remain elusive. Here we revealed the "cellulose degradome" for the model mesophilic cellulolytic bacterium Clostridium cellulolyticum ATCC 35319, via an integrated analysis of its complete genome, its transcriptomes under glucose, xylose, cellobiose, cellulose, xylan or corn stover and its extracellular proteomes under glucose, cellobiose or cellulose. RESULTS Proteins for core metabolic functions, environment sensing, gene regulation and polysaccharide metabolism were enriched in the cellulose degradome. Analysis of differentially expressed genes revealed a "core" set of 48 CAZymes required for degrading cellulose-containing substrates as well as an "accessory" set of 76 CAZymes required for specific non-cellulose substrates. Gene co-expression analysis suggested that Carbon Catabolite Repression (CCR) related regulators sense intracellular glycolytic intermediates and control the core CAZymes that mainly include cellulosomal components, whereas 11 sets of Two-Component Systems (TCSs) respond to availability of extracellular soluble sugars and respectively regulate most of the accessory CAZymes and associated transporters. Surprisingly, under glucose alone, the core cellulases were highly expressed at both transcript and protein levels. Furthermore, glucose enhanced cellulolysis in a dose-dependent manner, via inducing cellulase transcription at low concentrations. CONCLUSION A molecular model of cellulose degradome in C. cellulolyticum (Ccel) was proposed, which revealed the substrate-specificity of CAZymes and the transcriptional regulation of core cellulases by CCR where the glucose acts as a CCR inhibitor instead of a trigger. These features represent a distinct environment-sensing strategy for competing while collaborating for cellulose utilization, which can be exploited for process and genetic engineering of microbial cellulolysis.
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Affiliation(s)
- Chenggang Xu
- BioEnergy Genome Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China
| | - Ranran Huang
- BioEnergy Genome Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China
| | - Lin Teng
- BioEnergy Genome Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China
| | - Dongmei Wang
- BioEnergy Genome Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China
| | - Christopher L Hemme
- Institute for Environmental Genomics, Department of Botany and Microbiology, University of Oklahoma, Norman, OK 73072, USA
| | - Ilya Borovok
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv 69978, Israel
| | - Qiang He
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, TN 37996, USA
| | - Raphael Lamed
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv 69978, Israel
| | - Edward A Bayer
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Jizhong Zhou
- Institute for Environmental Genomics, Department of Botany and Microbiology, University of Oklahoma, Norman, OK 73072, USA
| | - Jian Xu
- BioEnergy Genome Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China
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25
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Pöther DC, Gierok P, Harms M, Mostertz J, Hochgräfe F, Antelmann H, Hamilton CJ, Borovok I, Lalk M, Aharonowitz Y, Hecker M. Distribution and infection-related functions of bacillithiol in Staphylococcus aureus. Int J Med Microbiol 2013; 303:114-23. [PMID: 23517692 DOI: 10.1016/j.ijmm.2013.01.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Revised: 01/24/2013] [Accepted: 01/27/2013] [Indexed: 12/17/2022] Open
Abstract
Bacillithiol (Cys-GlcN-malate, BSH) serves as a major low molecular weight thiol in low GC Gram-positive bacteria including Bacillus species and a variety of Staphylococcus aureus strains. These bacteria do not produce glutathione (GSH). In this study, HPLC analyses were used to determine BSH levels in different S. aureus strains. Furthermore, the role of BSH in the resistance against oxidants and antibiotics and its function in virulence was investigated. We and others (Newton, G.L., Fahey, R.C., Rawat, M., 2012. Microbiology 158, 1117-1126) found that BSH is not produced by members of the S. aureus NCTC8325 lineage, such as strains 8325-4 and SH1000. Using bioinformatics we show that the BSH-biosynthetic gene bshC is disrupted by an 8-bp duplication in S. aureus NCTC8325. The functional bshC-gene from BSH-producing S. aureus Newman (NWMN_1087) was expressed in S. aureus 8325-4 to reconstitute BSH-synthesis. Comparison of the BSH-producing and BSH-minus strains revealed higher resistance of the BSH-producing strain against the antibiotic fosfomycin and the oxidant hypochlorite but not against hydrogen peroxide or diamide. In addition, a higher bacterial load of the BSH-producing strain was detected in human upper-airway epithelial cells and murine macrophages. This indicates a potential role of BSH in protection of S. aureus during infection.
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Affiliation(s)
- Dierk-Christoph Pöther
- Institute of Microbiology, Ernst-Moritz-Arndt-University of Greifswald, 17487 Greifswald, Germany
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26
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Dassa B, Borovok I, Lamed R, Henrissat B, Coutinho P, Hemme CL, Huang Y, Zhou J, Bayer EA. Genome-wide analysis of acetivibrio cellulolyticus provides a blueprint of an elaborate cellulosome system. BMC Genomics 2012; 13:210. [PMID: 22646801 PMCID: PMC3413522 DOI: 10.1186/1471-2164-13-210] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Accepted: 05/30/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Microbial degradation of plant cell walls and its conversion to sugars and other byproducts is a key step in the carbon cycle on Earth. In order to process heterogeneous plant-derived biomass, specialized anaerobic bacteria use an elaborate multi-enzyme cellulosome complex to synergistically deconstruct cellulosic substrates. The cellulosome was first discovered in the cellulolytic thermophile, Clostridium thermocellum, and much of our knowledge of this intriguing type of protein composite is based on the cellulosome of this environmentally and biotechnologically important bacterium. The recently sequenced genome of the cellulolytic mesophile, Acetivibrio cellulolyticus, allows detailed comparison of the cellulosomes of these two select cellulosome-producing bacteria. RESULTS Comprehensive analysis of the A. cellulolyticus draft genome sequence revealed a very sophisticated cellulosome system. Compared to C. thermocellum, the cellulosomal architecture of A. cellulolyticus is much more extensive, whereby the genome encodes for twice the number of cohesin- and dockerin-containing proteins. The A. cellulolyticus genome has thus evolved an inflated number of 143 dockerin-containing genes, coding for multimodular proteins with distinctive catalytic and carbohydrate-binding modules that play critical roles in biomass degradation. Additionally, 41 putative cohesin modules distributed in 16 different scaffoldin proteins were identified in the genome, representing a broader diversity and modularity than those of Clostridium thermocellum. Although many of the A. cellulolyticus scaffoldins appear in unconventional modular combinations, elements of the basic structural scaffoldins are maintained in both species. In addition, both species exhibit similarly elaborate cell-anchoring and cellulosome-related gene- regulatory elements. CONCLUSIONS This work portrays a particularly intricate, cell-surface cellulosome system in A. cellulolyticus and provides a blueprint for examining the specific roles of the various cellulosomal components in the degradation of complex carbohydrate substrates of the plant cell wall by the bacterium.
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Affiliation(s)
- Bareket Dassa
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, Israel
| | - Ilya Borovok
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv, Tel Aviv, Israel
| | - Raphael Lamed
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv, Tel Aviv, Israel
| | - Bernard Henrissat
- Architecture et Fonction des Macromolecules Biologiques, CNRS and Universite Aix- Marseilles I & II, Marseilles, France
| | - Pedro Coutinho
- Architecture et Fonction des Macromolecules Biologiques, CNRS and Universite Aix- Marseilles I & II, Marseilles, France
| | - Christopher L Hemme
- Department of Botany and Microbiology, and Institute for Environmental Genomics, University of Oklahoma, Norman, OK, USA
| | - Yue Huang
- Department of Botany and Microbiology, and Institute for Environmental Genomics, University of Oklahoma, Norman, OK, USA
| | - Jizhong Zhou
- Department of Botany and Microbiology, and Institute for Environmental Genomics, University of Oklahoma, Norman, OK, USA
| | - Edward A Bayer
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, Israel
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Fraiberg M, Borovok I, Weiner RM, Lamed R, Bayer EA. Bacterial cadherin domains as carbohydrate binding modules: determination of affinity constants to insoluble complex polysaccharides. Methods Mol Biol 2012; 908:109-18. [PMID: 22843394 DOI: 10.1007/978-1-61779-956-3_11] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cadherin (CA) and cadherin-like (CADG) doublet domains from the complex polysaccharide-degrading marine bacterium, Saccharophagus degradans 2-40, demonstrated reversible calcium-dependent binding to different complex polysaccharides, which serve as growth substrates for the bacterium. Here we describe a procedure based on adsorption of CA and CADG doublet domains to different insoluble complex polysaccharides, followed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) for visualizing and quantifying the distribution of cadherins between the bound and unbound fractions. Scatchard plots were employed to determine the kinetics of interactions of CA and CADG with several complex carbohydrates. On the basis of these binding studies, the CA and CADG doublet domains are proposed to form a new family of carbohydrate-binding module (CBM).
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Affiliation(s)
- Milana Fraiberg
- Department of Molecular Microbiology and Biotechnology, The Daniella Rich Institute for Structural Biology, Tel Aviv University, Ramat Aviv, Israel
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28
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Brulc JM, Yeoman CJ, Wilson MK, Berg Miller ME, Jeraldo P, Jindou S, Goldenfeld N, Flint HJ, Lamed R, Borovok I, Vodovnik M, Nelson KE, Bayer EA, White BA. Cellulosomics, a gene-centric approach to investigating the intraspecific diversity and adaptation of Ruminococcus flavefaciens within the rumen. PLoS One 2011; 6:e25329. [PMID: 22043282 PMCID: PMC3197198 DOI: 10.1371/journal.pone.0025329] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2011] [Accepted: 09/01/2011] [Indexed: 01/28/2023] Open
Abstract
Background The bovine rumen maintains a diverse microbial community that serves to break down indigestible plant substrates. However, those bacteria specifically adapted to degrade cellulose, the major structural component of plant biomass, represent a fraction of the rumen microbiome. Previously, we proposed scaC as a candidate for phylotyping Ruminococcus flavefaciens, one of three major cellulolytic bacterial species isolated from the rumen. In the present report we examine the dynamics and diversity of scaC-types both within and between cattle temporally, following a dietary switch from corn-silage to grass-legume hay. These results were placed in the context of the overall bacterial population dynamics measured using the 16S rRNA. Principal Findings As many as 117 scaC-types were estimated, although just nineteen were detected in each of three rumens tested, and these collectively accounted for the majority of all types present. Variation in scaC populations was observed between cattle, between planktonic and fiber-associated fractions and temporally over the six-week survey, and appeared related to scaC phylogeny. However, by the sixth week no significant separation of scaC populations was seen between animals, suggesting enrichment of a constrained set of scaC-types. Comparing the amino-acid translation of each scaC-type revealed sequence variation within part of the predicted dockerin module but strong conservation in the N-terminus, where the cohesin module is located. Conclusions The R. flavefaciens species comprises a multiplicity of scaC-types in-vivo. Enrichment of particular scaC-types temporally, following a dietary switch, and between fractions along with the phylogenetic congruence suggests that functional differences exist between types. Observed differences in dockerin modules suggest at least part of the functional heterogeneity may be conferred by scaC. The polymorphic nature of scaC enables the relative distribution of R. flavefaciens strains to be examined and represents a gene-centric approach to investigating the intraspecific adaptation of an important specialist population.
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Affiliation(s)
- Jennifer M. Brulc
- Department of Animal Sciences, University of Illinois, Urbana, Illinois, United States of America
- The Institute for Genomic Biology, University of Illinois, Urbana, Illinois, United States of America
| | - Carl J. Yeoman
- The Institute for Genomic Biology, University of Illinois, Urbana, Illinois, United States of America
| | - Melissa K. Wilson
- Department of Animal Sciences, University of Illinois, Urbana, Illinois, United States of America
| | - Margret E. Berg Miller
- Department of Animal Sciences, University of Illinois, Urbana, Illinois, United States of America
- The Institute for Genomic Biology, University of Illinois, Urbana, Illinois, United States of America
| | - Patricio Jeraldo
- The Institute for Genomic Biology, University of Illinois, Urbana, Illinois, United States of America
- Department of Physics, University of Illinois, Urbana, Illinois, United States of America
| | - Sadanari Jindou
- Department of Culture Education, Faculty of Science, Meijo University, Nagoya, Aichi, Japan
| | - Nigel Goldenfeld
- The Institute for Genomic Biology, University of Illinois, Urbana, Illinois, United States of America
- Department of Physics, University of Illinois, Urbana, Illinois, United States of America
| | - Harry J. Flint
- Microbial Ecology Group, Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, United Kingdom
| | - Raphael Lamed
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv, Tel Aviv, Israel
| | - Ilya Borovok
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv, Tel Aviv, Israel
| | - Maša Vodovnik
- Microbial Ecology Group, Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, United Kingdom
- Chair for Microbiology and Microbial Biotechnology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Karen E. Nelson
- The J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Edward A. Bayer
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, Israel
| | - Bryan A. White
- Department of Animal Sciences, University of Illinois, Urbana, Illinois, United States of America
- The Institute for Genomic Biology, University of Illinois, Urbana, Illinois, United States of America
- * E-mail:
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Voronov-Goldman M, Lamed R, Noach I, Borovok I, Kwiat M, Rosenheck S, Shimon LJW, Bayer EA, Frolow F. Noncellulosomal cohesin from the hyperthermophilic archaeon Archaeoglobus fulgidus. Proteins 2011; 79:50-60. [PMID: 20954171 DOI: 10.1002/prot.22857] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2010] [Revised: 07/22/2010] [Accepted: 08/05/2010] [Indexed: 11/07/2022]
Abstract
The increasing numbers of published genomes has enabled extensive survey of protein sequences in nature. During the course of our studies on cellulolytic bacteria that produce multienzyme cellulosome complexes designed for efficient degradation of cellulosic substrates, we have investigated the intermodular cohesin-dockerin interaction, which provides the molecular basis for cellulosome assembly. An early search of the genome databases yielded the surprising existence of a dockerin-like sequence and two cohesin-like sequences in the hyperthermophilic noncellulolytic archaeon, Archaeoglobus fulgidus, which clearly contradicts the cellulosome paradigm. Here, we report a biochemical and biophysical analysis, which revealed particularly strong- and specific-binding interactions between these two cohesins and the single dockerin. The crystal structure of one of the recombinant cohesin modules was determined and found to resemble closely the type-I cohesin structure from the cellulosome of Clostridium thermocellum, with certain distinctive features: two of the loops in the archaeal cohesin structure are shorter than those of the C. thermocellum structure, and a large insertion of 27-amino acid residues, unique to the archaeal cohesin, appears to be largely disordered. Interestingly, the cohesin module undergoes reversible dimer and tetramer formation in solution, a property, which has not been observed previously for other cohesins. This is the first description of cohesin and dockerin interactions in a noncellulolytic archaeon and the first structure of an archaeal cohesin. This finding supports the notion that interactions based on the cohesin-dockerin paradigm are of more general occurrence and are not unique to the cellulosome system.
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Affiliation(s)
- Milana Voronov-Goldman
- Department of Molecular Microbiology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv 69978, Israel
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Malchin N, Molotsky T, Borovok I, Voziyanov Y, Kotlyar AB, Yagil E, Kolot M. High efficiency of a sequential recombinase-mediated cassette exchange reaction in Escherichia coli. J Mol Microbiol Biotechnol 2010; 19:117-22. [PMID: 20924197 DOI: 10.1159/000321497] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
A comparison between the efficiency of recombinase-mediated cassette exchange (RMCE) reactions catalyzed in Escherichia coli by the site-specific recombinases Flp of yeast and Int of coliphage HK022 has revealed that an Flp-catalyzed RMCE reaction is more efficient than an Int-HK022 catalyzed reaction. In contrast, an RMCE reaction with 1 pair of frt sites and 1 pair of att sites catalyzed in the presence of both recombinases is very inefficient. However, the same reaction catalyzed by each recombinase individually supplied in a sequential order is very efficient, regardless of the order. Atomic force microscopy images of Flp with its DNA substrates show that only 1 pair of recombination sites forms a synaptic complex with the recombinase. The results suggest that the RMCE reaction is sequential.
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Affiliation(s)
- Natalia Malchin
- Department of Biochemistry, Tel Aviv University, Tel Aviv, Israel
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31
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Bahari L, Gilad Y, Borovok I, Kahel-Raifer H, Dassa B, Nataf Y, Shoham Y, Lamed R, Bayer EA. Glycoside hydrolases as components of putative carbohydrate biosensor proteins in Clostridium thermocellum. J Ind Microbiol Biotechnol 2010; 38:825-32. [DOI: 10.1007/s10295-010-0848-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2010] [Accepted: 08/16/2010] [Indexed: 11/28/2022]
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Rincon MT, Dassa B, Flint HJ, Travis AJ, Jindou S, Borovok I, Lamed R, Bayer EA, Henrissat B, Coutinho PM, Antonopoulos DA, Berg Miller ME, White BA. Abundance and diversity of dockerin-containing proteins in the fiber-degrading rumen bacterium, Ruminococcus flavefaciens FD-1. PLoS One 2010; 5:e12476. [PMID: 20814577 PMCID: PMC2930009 DOI: 10.1371/journal.pone.0012476] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2010] [Accepted: 08/03/2010] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND The cellulosome is a multi-enzyme machine, which plays a key role in the breakdown of plant cell walls in many anaerobic cellulose-degrading microorganisms. Ruminococcus flavefaciens FD-1, a major fiber-degrading bacterium present in the gut of herbivores, has the most intricate cellulosomal organization thus far described. Cellulosome complexes are assembled through high-affinity cohesin-dockerin interactions. More than two-hundred dockerin-containing proteins have been identified in the R. flavefaciens genome, yet the reason for the expansion of these crucial cellulosomal components is yet unknown. METHODOLOGY/PRINCIPAL FINDINGS We have explored the full spectrum of 222 dockerin-containing proteins potentially involved in the assembly of cellulosome-like complexes of R. flavefaciens. Bioinformatic analysis of the various dockerin modules showed distinctive conservation patterns within their two Ca(2+)-binding repeats and their flanking regions. Thus, we established the conceptual framework for six major groups of dockerin types, according to their unique sequence features. Within this framework, the modular architecture of the parent proteins, some of which are multi-functional proteins, was evaluated together with their gene expression levels. Specific dockerin types were found to be associated with selected groups of functional components, such as carbohydrate-binding modules, numerous peptidases, and/or carbohydrate-active enzymes. In addition, members of other dockerin groups were linked to structural proteins, e.g., cohesin-containing proteins, belonging to the scaffoldins. CONCLUSIONS/SIGNIFICANCE This report profiles the abundance and sequence diversity of the R. flavefaciens FD-1 dockerins, and provides the molecular basis for future understanding of the potential for a wide array of cohesin-dockerin specificities. Conserved differences between dockerins may be reflected in their stability, function or expression within the context of the parent protein, in response to their role in the rumen environment.
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Affiliation(s)
- Marco T. Rincon
- Microbial Ecology Group, Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, United Kingdom
| | - Bareket Dassa
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, Israel
| | - Harry J. Flint
- Microbial Ecology Group, Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, United Kingdom
| | - Anthony J. Travis
- Microbial Ecology Group, Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, United Kingdom
| | - Sadanari Jindou
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv, Israel
| | - Ilya Borovok
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv, Israel
| | - Raphael Lamed
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv, Israel
| | - Edward A. Bayer
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, Israel
| | - Bernard Henrissat
- Architecture et Fonction des Macromolecules Biologiques, CNRS and Universites d'Aix-Marseille I & II, Marseille, France
| | - Pedro M. Coutinho
- Architecture et Fonction des Macromolecules Biologiques, CNRS and Universites d'Aix-Marseille I & II, Marseille, France
| | - Dion A. Antonopoulos
- Division of Nutritional Sciences, Department of Animal Sciences, North American Consortium for Genomics of Fibrolytic Ruminal Bacteria, University of Illinois, Urbana, Illinois, United States of America
| | - Margret E. Berg Miller
- Division of Nutritional Sciences, Department of Animal Sciences, North American Consortium for Genomics of Fibrolytic Ruminal Bacteria, University of Illinois, Urbana, Illinois, United States of America
| | - Bryan A. White
- Division of Nutritional Sciences, Department of Animal Sciences, North American Consortium for Genomics of Fibrolytic Ruminal Bacteria, University of Illinois, Urbana, Illinois, United States of America
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Kahel-Raifer H, Jindou S, Bahari L, Nataf Y, Shoham Y, Bayer EA, Borovok I, Lamed R. The unique set of putative membrane-associated anti-sigma factors in Clostridium thermocellum suggests a novel extracellular carbohydrate-sensing mechanism involved in gene regulation. FEMS Microbiol Lett 2010; 308:84-93. [PMID: 20487018 DOI: 10.1111/j.1574-6968.2010.01997.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Genome analysis of the Gram-positive cellulolytic bacterium Clostridium thermocellum revealed the presence of multiple negative regulators of alternative sigma factors. Nine of the deduced proteins share a strong similarity in their N-terminal sequences to the Bacillus subtilis membrane-associated anti-sigma(I) factor RsgI and have an unusual domain organization. In six RsgI-like proteins, the C-terminal sequences contain predicted carbohydrate-binding modules. Three of these modules were overexpressed and shown to bind specifically to cellulose and/or pectin. Bioinformatic analysis of >1200 bacterial genomes revealed that the C. thermocellum RsgI-like proteins are unique to this species and are not present in other cellulolytic clostridial species (e.g. Clostridium cellulolyticum and Clostridium papyrosolvens). Eight of the nine genes encoding putative C. thermocellum RsgI-like anti-sigma factors form predicted bicistronic operons, in which the first gene encodes a putative alternative sigma factor, similar to B. subtilissigma(I), but lacking in one of its domains. These observations suggest a novel carbohydrate-sensing mechanism in C. thermocellum, whereby the presence of polysaccharide biomass components is detected extracellularly and the signal is transmitted intracellularly, resulting in the disruption of the interaction between RsgI-like proteins and sigma(I)-like factors, the latter of which serve to activate appropriate genes encoding proteins involved in cellulose utilization.
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Affiliation(s)
- Hamutal Kahel-Raifer
- Department of Molecular Microbiology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
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Berg Miller ME, Antonopoulos DA, Rincon MT, Band M, Bari A, Akraiko T, Hernandez A, Thimmapuram J, Henrissat B, Coutinho PM, Borovok I, Jindou S, Lamed R, Flint HJ, Bayer EA, White BA. Diversity and strain specificity of plant cell wall degrading enzymes revealed by the draft genome of Ruminococcus flavefaciens FD-1. PLoS One 2009; 4:e6650. [PMID: 19680555 PMCID: PMC2721979 DOI: 10.1371/journal.pone.0006650] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2009] [Accepted: 07/07/2009] [Indexed: 11/19/2022] Open
Abstract
Background Ruminococcus flavefaciens is a predominant cellulolytic rumen bacterium, which forms a multi-enzyme cellulosome complex that could play an integral role in the ability of this bacterium to degrade plant cell wall polysaccharides. Identifying the major enzyme types involved in plant cell wall degradation is essential for gaining a better understanding of the cellulolytic capabilities of this organism as well as highlighting potential enzymes for application in improvement of livestock nutrition and for conversion of cellulosic biomass to liquid fuels. Methodology/Principal Findings The R. flavefaciens FD-1 genome was sequenced to 29x-coverage, based on pulsed-field gel electrophoresis estimates (4.4 Mb), and assembled into 119 contigs providing 4,576,399 bp of unique sequence. As much as 87.1% of the genome encodes ORFs, tRNA, rRNAs, or repeats. The GC content was calculated at 45%. A total of 4,339 ORFs was detected with an average gene length of 918 bp. The cellulosome model for R. flavefaciens was further refined by sequence analysis, with at least 225 dockerin-containing ORFs, including previously characterized cohesin-containing scaffoldin molecules. These dockerin-containing ORFs encode a variety of catalytic modules including glycoside hydrolases (GHs), polysaccharide lyases, and carbohydrate esterases. Additionally, 56 ORFs encode proteins that contain carbohydrate-binding modules (CBMs). Functional microarray analysis of the genome revealed that 56 of the cellulosome-associated ORFs were up-regulated, 14 were down-regulated, 135 were unaffected, when R. flavefaciens FD-1 was grown on cellulose versus cellobiose. Three multi-modular xylanases (ORF01222, ORF03896, and ORF01315) exhibited the highest levels of up-regulation. Conclusions/Significance The genomic evidence indicates that R. flavefaciens FD-1 has the largest known number of fiber-degrading enzymes likely to be arranged in a cellulosome architecture. Functional analysis of the genome has revealed that the growth substrate drives expression of enzymes predicted to be involved in carbohydrate metabolism as well as expression and assembly of key cellulosomal enzyme components.
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Affiliation(s)
- Margret E. Berg Miller
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Dionysios A. Antonopoulos
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Marco T. Rincon
- Microbial Ecology Group, Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, United Kingdom
| | - Mark Band
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Albert Bari
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Tatsiana Akraiko
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Alvaro Hernandez
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Jyothi Thimmapuram
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Bernard Henrissat
- Architecture et Fonction des Macromolécules Biologiques, CNRS and Universités Aix-Marseille I & II, Marseille, France
| | - Pedro M. Coutinho
- Architecture et Fonction des Macromolécules Biologiques, CNRS and Universités Aix-Marseille I & II, Marseille, France
| | - Ilya Borovok
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv, Israel
| | - Sadanari Jindou
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv, Israel
| | - Raphael Lamed
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv, Israel
| | - Harry J. Flint
- Microbial Ecology Group, Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, United Kingdom
| | - Edward A. Bayer
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, Israel
| | - Bryan A. White
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
- * E-mail:
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Jochmann N, Kurze AK, Czaja LF, Brinkrolf K, Brune I, Hüser AT, Hansmeier N, Pühler A, Borovok I, Tauch A. Genetic makeup of the Corynebacterium glutamicum LexA regulon deduced from comparative transcriptomics and in vitro DNA band shift assays. Microbiology (Reading) 2009; 155:1459-1477. [PMID: 19372162 DOI: 10.1099/mic.0.025841-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The lexA gene of Corynebacterium glutamicum ATCC 13032 was deleted to create the mutant strain C. glutamicum NJ2114, which has an elongated cell morphology and an increased doubling time. To characterize the SOS regulon in C. glutamicum, the transcriptomes of NJ2114 and a DNA-damage-induced wild-type strain were compared with that of a wild-type control using DNA microarray hybridization. The expression data were combined with bioinformatic pattern searches for LexA binding sites, leading to the detection of 46 potential SOS boxes located upstream of differentially expressed transcription units. Binding of a hexahistidyl-tagged LexA protein to 40 double-stranded oligonucleotides containing the potential SOS boxes was demonstrated in vitro by DNA band shift assays. It turned out that LexA binds not only to SOS boxes in the promoter-operator region of upregulated genes, but also to SOS boxes detected upstream of downregulated genes. These results demonstrated that LexA controls directly the expression of at least 48 SOS genes organized in 36 transcription units. The deduced genes encode a variety of physiological functions, many of them involved in DNA repair and survival after DNA damage, but nearly half of them have hitherto unknown functions. Alignment of the LexA binding sites allowed the corynebacterial SOS box consensus sequence TcGAA(a/c)AnnTGTtCGA to be deduced. Furthermore, the common intergenic region of lexA and the differentially expressed divS-nrdR operon, encoding a cell division suppressor and a regulator of deoxyribonucleotide biosynthesis, was characterized in detail. Promoter mapping revealed differences in divS-nrdR expression during SOS response and normal growth conditions. One of the four LexA binding sites detected in the intergenic region is involved in regulating divS-nrdR transcription, whereas the other sites are apparently used for negative autoregulation of lexA expression.
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Affiliation(s)
- Nina Jochmann
- International NRW Graduate School in Bioinformatics and Genome Research, Centrum für Biotechnologie, Universität Bielefeld, Universitätsstraße 25, D-33615 Bielefeld, Germany.,Institut für Genomforschung und Systembiologie, Centrum für Biotechnologie, Universität Bielefeld, Universitätsstraße 27, D-33615 Bielefeld, Germany
| | - Anna-Katharina Kurze
- Institut für Genomforschung und Systembiologie, Centrum für Biotechnologie, Universität Bielefeld, Universitätsstraße 27, D-33615 Bielefeld, Germany
| | - Lisa F Czaja
- Institut für Genomforschung und Systembiologie, Centrum für Biotechnologie, Universität Bielefeld, Universitätsstraße 27, D-33615 Bielefeld, Germany
| | - Karina Brinkrolf
- Institut für Genomforschung und Systembiologie, Centrum für Biotechnologie, Universität Bielefeld, Universitätsstraße 27, D-33615 Bielefeld, Germany
| | - Iris Brune
- Institut für Genomforschung und Systembiologie, Centrum für Biotechnologie, Universität Bielefeld, Universitätsstraße 27, D-33615 Bielefeld, Germany
| | - Andrea T Hüser
- Institut für Genomforschung und Systembiologie, Centrum für Biotechnologie, Universität Bielefeld, Universitätsstraße 27, D-33615 Bielefeld, Germany
| | - Nicole Hansmeier
- Department of Physics, Arizona State University, Tempe, AZ 85287-1504, USA
| | - Alfred Pühler
- Institut für Genomforschung und Systembiologie, Centrum für Biotechnologie, Universität Bielefeld, Universitätsstraße 27, D-33615 Bielefeld, Germany
| | - Ilya Borovok
- George S. Wise Faculty of Life Sciences, Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv 69978, Israel
| | - Andreas Tauch
- Institut für Genomforschung und Systembiologie, Centrum für Biotechnologie, Universität Bielefeld, Universitätsstraße 27, D-33615 Bielefeld, Germany
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Voronov-Goldman M, Noach I, Lamed R, Shimon LJW, Borovok I, Bayer EA, Frolow F. Crystallization and preliminary X-ray analysis of a cohesin-like module from AF2375 of the archaeon Archaeoglobus fulgidus. Acta Crystallogr Sect F Struct Biol Cryst Commun 2009; 65:275-8. [PMID: 19255482 PMCID: PMC2650457 DOI: 10.1107/s1744309109002887] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2008] [Accepted: 01/23/2009] [Indexed: 11/10/2022]
Abstract
A cohesin-like module of 160 amino-acid residues from the hypothetical protein AF2375 of the noncellulolytic, hyperthermophilic, sulfate-reducing archaeon Archaeoglobus fulgidus was cloned, expressed, purified, crystallized and subjected to X-ray structural study in order to compare its structure with those of cellulolytic cohesins. The crystals had cubic symmetry, with unit-cell parameters a = b = c = 101.75 A in space group P4(3)32, and diffracted to 1.82 A resolution. The asymmetric unit contained a single cohesin molecule. A model assembled from six cohesin structures (PDB entries 1anu, 1aoh, 1g1k, 1qzn, 1zv9 and 1tyj) of very low sequence identity to the cohesin-like module was used in molecular-replacement attempts, producing a marginal solution.
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Affiliation(s)
- Milana Voronov-Goldman
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv 69978, Israel
- The Daniella Rich Institute for Structural Biology, Tel Aviv University, Tel Aviv 69978, Israel
| | - Ilit Noach
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Raphael Lamed
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv 69978, Israel
- The Daniella Rich Institute for Structural Biology, Tel Aviv University, Tel Aviv 69978, Israel
| | - Linda J. W. Shimon
- Department of Chemical Support, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Ilya Borovok
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv 69978, Israel
| | - Edward A. Bayer
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Felix Frolow
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv 69978, Israel
- The Daniella Rich Institute for Structural Biology, Tel Aviv University, Tel Aviv 69978, Israel
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Abstract
The high-affinity cohesin-dockerin interaction was originally discovered as modular components, which mediate the assembly of the various subunits of the multienzyme cellulosome complex that characterizes some cellulolytic bacteria. Until recently, the presence of cohesins and dockerins within a bacterial proteome was considered a definitive signature of a cellulosome-producing bacterium. Widespread genome sequencing has since revealed a wealth of putative cohesin- and dockerin-containing proteins in Bacteria, Archaea, and in primitive eukaryotes. The newly identified modules appear to serve diverse functions that are clearly distinct from the classical cellulosome archetype, and the vast majority of parent proteins are not predicted glycoside hydrolases. In most cases, only a few such genes have been identified in a given microorganism, which encode proteins containing but a single cohesin and/or dockerin. In some cases, one or the other module appears to be missing from a given species, and in other cases both modules occur within the same protein. This review provides a bioinformatics-based survey of the current status of cohesin- and dockerin-like sequences in species from the Bacteria, Archaea, and Eukarya. Surprisingly, many identified modules and their parent proteins are clearly unrelated to cellulosomes. The cellulosome paradigm may thus be the exception rather than the rule for bacterial, archaeal, and eukaryotic employment of cohesin and dockerin modules.
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Affiliation(s)
- Ayelet Peer
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv, Israel
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Jindou S, Brulc JM, Levy-Assaraf M, Rincon MT, Flint HJ, Berg ME, Wilson MK, White BA, Bayer EA, Lamed R, Borovok I. Cellulosome gene cluster analysis for gauging the diversity of the ruminal cellulolytic bacterium Ruminococcus flavefaciens. FEMS Microbiol Lett 2008; 285:188-94. [PMID: 18564339 DOI: 10.1111/j.1574-6968.2008.01234.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Ruminococcus flavefaciens is a vital cellulosome-producing fibrolytic rumen bacterium. The arrangement of the cellulosomal scaffoldin gene cluster (scaC-scaA-scaB-cttA-scaE) is conserved in two R. flavefaciens strains (17 and FD-1). Sequence analysis revealed a high mosaic conservation of the intergenic regions in the two strains that contrasted sharply with the divergence of the structural sca gene sequences. Based on the conserved intergenic regions, we designed PCR primers in order to examine the sca gene cluster in additional R. flavefaciens strains (C94, B34b, C1a and JM1). Using these conserved and/or degenerate primers, the scaC, scaA and scaB genes were amplified in all six strains, while the entire sca gene cluster and the proximal genes cttA and scaE were successfully amplified in four of the strains (17, FD-1, C94 and JM1). The sequencing of scaA and scaC genes in all the strains yielded additional insight into the variability of the structural genes with regard to the number and type of cohesin modules contained in a conserved molecular skeleton. Moreover, the scaC gene, being short and variable, appears to be a promising functional phylotyping target for metagenomic population studies of R. flavefaciens in the rumen as a function of the individual host animal.
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MESH Headings
- Animals
- Bacterial Proteins/genetics
- Cell Cycle Proteins/genetics
- Cellulosomes/genetics
- Chromosomal Proteins, Non-Histone/genetics
- DNA Primers/genetics
- DNA, Bacterial/chemistry
- DNA, Bacterial/genetics
- DNA, Intergenic
- DNA, Ribosomal/chemistry
- DNA, Ribosomal/genetics
- Gene Order
- Genes, Bacterial
- Molecular Sequence Data
- Multigene Family
- Phylogeny
- Polymerase Chain Reaction/methods
- Polymorphism, Genetic
- Protein Structure, Tertiary
- RNA, Ribosomal, 16S/genetics
- Ruminococcus/classification
- Ruminococcus/genetics
- Sequence Analysis, DNA
- Synteny
- Cohesins
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Affiliation(s)
- Sadanari Jindou
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv, Israel
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39
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Weiner RM, Taylor LE, Henrissat B, Hauser L, Land M, Coutinho PM, Rancurel C, Saunders EH, Longmire AG, Zhang H, Bayer EA, Gilbert HJ, Larimer F, Zhulin IB, Ekborg NA, Lamed R, Richardson PM, Borovok I, Hutcheson S. Complete genome sequence of the complex carbohydrate-degrading marine bacterium, Saccharophagus degradans strain 2-40 T. PLoS Genet 2008; 4:e1000087. [PMID: 18516288 PMCID: PMC2386152 DOI: 10.1371/journal.pgen.1000087] [Citation(s) in RCA: 133] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2007] [Accepted: 05/01/2008] [Indexed: 01/02/2023] Open
Abstract
The marine bacterium Saccharophagus degradans strain 2-40 (Sde 2-40) is emerging as a vanguard of a recently discovered group of marine and estuarine bacteria that recycles complex polysaccharides. We report its complete genome sequence, analysis of which identifies an unusually large number of enzymes that degrade >10 complex polysaccharides. Not only is this an extraordinary range of catabolic capability, many of the enzymes exhibit unusual architecture including novel combinations of catalytic and substrate-binding modules. We hypothesize that many of these features are adaptations that facilitate depolymerization of complex polysaccharides in the marine environment. This is the first sequenced genome of a marine bacterium that can degrade plant cell walls, an important component of the carbon cycle that is not well-characterized in the marine environment. A segment of the global marine carbon cycle that has been poorly characterized is the mineralization of complex polysaccharides to carbon dioxide, a greenhouse gas. It also remained a mystery whether prokaryotes mineralize plant/algal cell walls and woody material in the oceans via carbohydrase systems and, if so, which organisms are involved. We have analyzed the complete genome sequence of the marine bacterium Saccharophagus degradans to better ascertain the potential role of prokaryotes in marine carbon transformation. We discovered that S. degradans, which is related to a number of other newly discovered marine strains, has an unprecedented quantity and diversity of carbohydrases, including the first characterized marine cellulose system. In fact, extensive analysis of the S. degradans genome sequence and functional followup experiments identified an extensive collection of complete enzyme systems that degrade more than 10 complex polysaccharides. These include agar, alginate, and chitin, altogether representing an extraordinary range of catabolic capability. Genomic analyses further demonstrated that the carbohydrases are unusually modular; sequence comparisons revealed that many of the functional modules were acquired by lateral transfer. These results suggest that the prokaryotic contribution to marine carbon fluxes is substantial and cannot be ignored in predictions of climate change.
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Affiliation(s)
- Ronald M. Weiner
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland, United States of America
- Marine and Estuarine Environmental Sciences Program, University of Maryland, College Park, Maryland, United States of America
- * E-mail: (RMW); (SH)
| | - Larry E. Taylor
- Marine and Estuarine Environmental Sciences Program, University of Maryland, College Park, Maryland, United States of America
| | - Bernard Henrissat
- Architecture et Fonction des Macromolécules Biologiques, UMR6098, CNRS, Universités Aix-Marseille I & II, Marseille, France
| | - Loren Hauser
- Oak Ridge National Laboratory (ORNL), Life Sciences Division, Oak Ridge, Tennessee, United States of America
| | - Miriam Land
- Oak Ridge National Laboratory (ORNL), Life Sciences Division, Oak Ridge, Tennessee, United States of America
| | - Pedro M. Coutinho
- Architecture et Fonction des Macromolécules Biologiques, UMR6098, CNRS, Universités Aix-Marseille I & II, Marseille, France
| | - Corinne Rancurel
- Architecture et Fonction des Macromolécules Biologiques, UMR6098, CNRS, Universités Aix-Marseille I & II, Marseille, France
| | - Elizabeth H. Saunders
- Joint Genome Institute, Group B-5 Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
| | - Atkinson G. Longmire
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland, United States of America
| | - Haitao Zhang
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland, United States of America
| | - Edward A. Bayer
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot, Israel
| | - Harry J. Gilbert
- Institute for Cell and Molecular Biosciences, University of Newcastle upon Tyne, Newcastle upon Tyne, United Kingdom
| | - Frank Larimer
- Oak Ridge National Laboratory (ORNL), Life Sciences Division, Oak Ridge, Tennessee, United States of America
| | - Igor B. Zhulin
- Joint Institute for Computational Sciences, University of Tennessee–Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
| | - Nathan A. Ekborg
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland, United States of America
| | - Raphael Lamed
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv, Israel
| | - Paul M. Richardson
- DOE Joint Genome Institute, Production Genomics Facility, Walnut Creek, California, United States of America
| | - Ilya Borovok
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv, Israel
| | - Steven Hutcheson
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland, United States of America
- * E-mail: (RMW); (SH)
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40
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Makhlin J, Kofman T, Borovok I, Kohler C, Engelmann S, Cohen G, Aharonowitz Y. Staphylococcus aureus ArcR controls expression of the arginine deiminase operon. J Bacteriol 2007; 189:5976-86. [PMID: 17557828 PMCID: PMC1952046 DOI: 10.1128/jb.00592-07] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We identified a single open reading frame that is strongly similar to ArcR, a member of the Crp/Fnr family of bacterial transcriptional regulators, in all sequenced Staphylococcus aureus genomes. The arcR gene encoding ArcR forms an operon with the arginine deiminase (ADI) pathway genes arcABDC that enable the utilization of arginine as a source of energy for growth under anaerobic conditions. In this report, we show that under anaerobic conditions, S. aureus growth is subject to glucose catabolic repression and is enhanced by arginine. Likewise, glucose and arginine have reciprocal effects on the transcription of the arcABDCR genes. Furthermore, we show using a mutant deleted for arcR that the transcription of the arc operon under anaerobic conditions depends strictly on a functional ArcR. These findings are supported by proteome analyses, which showed that under anaerobic conditions the expression of the ADI catabolic proteins depends on ArcR. Bioinformatic analysis of S. aureus ArcR predicts an N-terminal nucleotide binding domain and a C-terminal helix-turn-helix DNA binding motif. ArcR binds to a conserved Crp-like sequence motif, TGTGA-N(6)-TCACA, present in the arc promoter region and thereby activates the expression of the ADI pathway genes. Crp-like sequence motifs were also found in the regulatory regions of some 30 other S. aureus genes mostly encoding anaerobic enzymatic systems, virulence factors, and regulatory systems. ArcR was tested and found to bind to the regulatory regions of four such genes, adh1, lctE, srrAB, and lukM. In one case, for lctE, encoding l-lactate dehydrogenase, ArcR was able to bind only in the presence of cyclic AMP. These observations suggest that ArcR is likely to play an important role in the expression of numerous genes required for anaerobic growth.
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Affiliation(s)
- Julia Makhlin
- Department of Molecular Microbiology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
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41
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Torrents E, Grinberg I, Gorovitz-Harris B, Lundström H, Borovok I, Aharonowitz Y, Sjöberg BM, Cohen G. NrdR controls differential expression of the Escherichia coli ribonucleotide reductase genes. J Bacteriol 2007; 189:5012-21. [PMID: 17496099 PMCID: PMC1951866 DOI: 10.1128/jb.00440-07] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Escherichia coli possesses class Ia, class Ib, and class III ribonucleotide reductases (RNR). Under standard laboratory conditions, the aerobic class Ia nrdAB RNR genes are well expressed, whereas the aerobic class Ib nrdEF RNR genes are poorly expressed. The class III RNR is normally expressed under microaerophilic and anaerobic conditions. In this paper, we show that the E. coli YbaD protein differentially regulates the expression of the three sets of genes. YbaD is a homolog of the Streptomyces NrdR protein. It is not essential for growth and has been renamed NrdR. Previously, Streptomyces NrdR was shown to transcriptionally regulate RNR genes by binding to specific 16-bp sequence motifs, NrdR boxes, located in the regulatory regions of its RNR operons. All three E. coli RNR operons contain two such NrdR box motifs positioned in their regulatory regions. The NrdR boxes are located near to or overlap with the promoter elements. DNA binding experiments showed that NrdR binds to each of the upstream regulatory regions. We constructed deletions in nrdR (ybaD) and showed that they caused high-level induction of transcription of the class Ib RNR genes but had a much smaller effect on induction of transcription of the class Ia and class III RNR genes. We propose a model for differential regulation of the RNR genes based on binding of NrdR to the regulatory regions. The model assumes that differences in the positions of the NrdR binding sites, and in the sequences of the motifs themselves, determine the extent to which NrdR represses the transcription of each RNR operon.
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Affiliation(s)
- Eduard Torrents
- Department of Molecular Biology and Functional Genomics, Stockholm University, SE-10691 Stockholm, Sweden
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42
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Zhang S, Borovok I, Aharonowitz Y, Sharan R, Bafna V. A sequence-based filtering method for ncRNA identification and its application to searching for riboswitch elements. Bioinformatics 2006; 22:e557-65. [PMID: 16873520 DOI: 10.1093/bioinformatics/btl232] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
MOTIVATION Recent studies have uncovered an "RNA world", in which non coding RNA (ncRNA) sequences play a central role in the regulation of gene expression. Computational studies on ncRNA have been directed toward developing detection methods for ncRNAs. State-of-the-art methods for the problem, like covariance models, suffer from high computational cost, underscoring the need for efficient filtering approaches that can identify promising sequence segments and speedup the detection process. RESULTS In this paper we make several contributions toward this goal. First, we formalize the concept of a filter and provide figures of merit that allow comparison between filters. Second, we design efficient sequence based filters that dominate the current state-of-the-art HMM filters. Third, we provide a new formulation of the covariance model that allows speeding up RNA alignment. We demonstrate the power of our approach on both synthetic data and real bacterial genomes. We then apply our algorithm to the detection of novel riboswitch elements from the whole bacterial and archaeal genomes. Our results point to a number of novel riboswitch candidates, and include genomes that were not previously known to contain riboswitches. AVAILABILITY The program is available upon request from the authors.
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Affiliation(s)
- Shaojie Zhang
- Department of Computer Science and Engineering, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA.
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43
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Jindou S, Borovok I, Rincon MT, Flint HJ, Antonopoulos DA, Berg ME, White BA, Bayer EA, Lamed R. Conservation and divergence in cellulosome architecture between two strains of Ruminococcus flavefaciens. J Bacteriol 2006; 188:7971-6. [PMID: 16997963 PMCID: PMC1636321 DOI: 10.1128/jb.00973-06] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A 17-kb scaffoldin gene cluster in Ruminococcus flavefaciens strain FD-1 was compared with the homologous segment published for strain 17. Although the general design of the cluster is identical in the two strains, significant differences in the modular architecture of the scaffoldin proteins were discovered, implying strain-specific divergence in cellulosome organization.
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Affiliation(s)
- Sadanari Jindou
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel
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44
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Grinberg I, Shteinberg T, Gorovitz B, Aharonowitz Y, Cohen G, Borovok I. The Streptomyces NrdR transcriptional regulator is a Zn ribbon/ATP cone protein that binds to the promoter regions of class Ia and class II ribonucleotide reductase operons. J Bacteriol 2006; 188:7635-44. [PMID: 16950922 PMCID: PMC1636249 DOI: 10.1128/jb.00903-06] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Ribonucleotide reductases (RNRs) catalyze the conversion of ribonucleotides to deoxyribonucleotides and are essential for de novo DNA synthesis and repair. Streptomyces spp. contain genes coding for two RNRs, either of which is sufficient for vegetative growth. The class Ia RNR is encoded by the nrdAB genes, and the class II RNR is encoded by nrdJ, which is coexpressed with nrdR. We previously showed that the Streptomyces coelicolor nrdR gene encodes a protein, NrdR, which represses transcription of both sets of RNR genes. NrdR is a member of a highly conserved family of proteins that is confined exclusively to prokaryotes. In this report, we describe a physical and biochemical characterization of the S. coelicolor NrdR protein and show that it is a zinc-ATP/dATP-containing protein that binds to the promoter regions of both Streptomyces RNR operons. The NrdR N terminus contains a zinc ribbon motif that is necessary for binding to the upstream regulatory region of both RNR operons. The latter contains two 16-bp direct repeat sequences, termed NrdR boxes, which are located proximal to, or overlap with, the promoter regions. These experiments support the view that NrdR controls the transcription of RNR genes by binding to the NrdR box sequences. We also show that the central NrdR ATP cone domain binds ATP and dATP and that mutations that abolish ATP/dATP binding significantly reduce DNA binding, suggesting that the ATP cone domain may allosterically regulate NrdR binding. We conclude that NrdR is a widely conserved regulator of RNR genes, binding to specific sequence elements in the promoter region and thereby modulating transcription.
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Affiliation(s)
- Inna Grinberg
- The George S. Wise Faculty of Life Sciences, Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv, 69978, Tel Aviv, Israel
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45
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Borovok I, Gorovitz B, Schreiber R, Aharonowitz Y, Cohen G. Coenzyme B12 controls transcription of the Streptomyces class Ia ribonucleotide reductase nrdABS operon via a riboswitch mechanism. J Bacteriol 2006; 188:2512-20. [PMID: 16547038 PMCID: PMC1428431 DOI: 10.1128/jb.188.7.2512-2520.2006] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Ribonucleotide reductases (RNRs) catalyze the conversion of ribonucleotides to deoxyribonucleotides and are essential for de novo DNA synthesis and repair. Streptomycetes contain genes coding for two RNRs. The class Ia RNR is oxygen dependent, and the class II RNR is oxygen independent and requires coenzyme B12. Either RNR is sufficient for vegetative growth. We show here that the Streptomyces coelicolor M145 nrdABS genes encoding the class Ia RNR are regulated by coenzyme B12. The 5'-untranslated region of nrdABS contains a 123-nucleotide B12 riboswitch. Similar B12 riboswitches are present in the corresponding regions of eight other S. coelicolor genes. The effect of B12 on growth and nrdABS transcription was examined in a mutant in which the nrdJ gene, encoding the class II RNR, was deleted. B12 concentrations of just 1 mug/liter completely inhibited growth of the NrdJ mutant strain. Likewise, B12 significantly reduced nrdABS transcription. To further explore the mechanism of B12 repression, we isolated in the nrdJ deletion strain mutants that are insensitive to B12 inhibition of growth. Two classes of mutations were found to map to the B12 riboswitch. Both conferred resistance to B12 inhibition of nrdABS transcription and are likely to affect B12 binding. These results establish that B12 regulates overall RNR expression in reciprocal ways, by riboswitch regulation of the class Ia RNR nrdABS genes and by serving as a cofactor for the class II RNR.
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Affiliation(s)
- Ilya Borovok
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv 69978, Israel
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46
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Gopal S, Borovok I, Ofer A, Yanku M, Cohen G, Goebel W, Kreft J, Aharonowitz Y. A multidomain fusion protein in Listeria monocytogenes catalyzes the two primary activities for glutathione biosynthesis. J Bacteriol 2005; 187:3839-47. [PMID: 15901709 PMCID: PMC1112035 DOI: 10.1128/jb.187.11.3839-3847.2005] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Glutathione is the predominant low-molecular-weight peptide thiol present in living organisms and plays a key role in protecting cells against oxygen toxicity. Until now, glutathione synthesis was thought to occur solely through the consecutive action of two physically separate enzymes, gamma-glutamylcysteine ligase and glutathione synthetase. In this report we demonstrate that Listeria monocytogenes contains a novel multidomain protein (termed GshF) that carries out complete synthesis of glutathione. Evidence for this comes from experiments which showed that in vitro recombinant GshF directs the formation of glutathione from its constituent amino acids and the in vivo effect of a mutation in GshF that abolishes glutathione synthesis, results in accumulation of the intermediate gamma-glutamylcysteine, and causes hypersensitivity to oxidative agents. We identified GshF orthologs, consisting of a gamma-glutamylcysteine ligase (GshA) domain fused to an ATP-grasp domain, in 20 gram-positive and gram-negative bacteria. Remarkably, 95% of these bacteria are mammalian pathogens. A plausible origin for GshF-dependent glutathione biosynthesis in these bacteria was the recruitment by a GshA ancestor gene of an ATP-grasp gene and the subsequent spread of the fusion gene between mammalian hosts, most likely by horizontal gene transfer.
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Affiliation(s)
- Shubha Gopal
- Tel Aviv University, The George S. Wise Faculty of Life Sciences, Department of Molecular Microbiology and Biotechnology, Ramat Aviv, 69978, Tel Aviv, Israel
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47
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Borovok I, Gorovitz B, Yanku M, Schreiber R, Gust B, Chater K, Aharonowitz Y, Cohen G. Alternative oxygen-dependent and oxygen-independent ribonucleotide reductases in Streptomyces: cross-regulation and physiological role in response to oxygen limitation. Mol Microbiol 2004; 54:1022-35. [PMID: 15522084 DOI: 10.1111/j.1365-2958.2004.04325.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Ribonucleotide reductases (RNRs) catalyse the conversion of ribonucleotides to deoxyribonucleotides and are essential for de novo DNA synthesis and repair. Streptomyces spp. contain genes coding for two RNRs. We show here that the Streptomyces coelicolor M145 nrdAB genes encoding an oxygen-dependent class I RNR are co-transcribed with nrdS, which encodes an AraC-like regulatory protein. Likewise, the class II oxygen-independent RNR nrdJ gene forms an operon with a likely regulatory gene, nrdR, which encodes a protein possessing an ATP-cone domain like those present in the allosteric activity site of many class Ia RNRs. Deletions in nrdB and nrdJ had no discernible effect on growth individually, but abolition of both RNR systems, using hydroxyurea to inactivate the class Ia RNR (NrdAB) in the nrdJ deletion mutant, was lethal, establishing that S. coelicolor possesses just two functional RNR systems. The class II RNR (NrdJ) may function to provide a pool of deoxyribonucleotide precursors for DNA repair during oxygen limitation and/or for immediate growth after restoration of oxygen, as the nrdJ mutant was slower in growth recovery than the nrdB mutant or the parent strain. The class Ia and class II RNR genes show complex regulation. The nrdRJ genes were transcribed some five- to sixfold higher than the nrdABS genes in vegetative growth, but when nrdJ was deleted, nrdABS transcription was upregulated by 13-fold. In a reciprocal experiment, deletion of nrdB had little effect on nrdRJ transcription. Deletion of nrdR caused a dramatic increase in transcription of nrdJ and to a less extent nrdABS, whereas disruption of cobN, a gene required for synthesis of coenzyme B12 a cofactor for the class II RNR, caused similar upregulation of transcription of nrdRJ and nrdABS. In contrast, deletion of nrdS had no detectable effect on transcription of either set of RNR genes. These results establish the existence of control mechanisms that sense and regulate overall RNR gene expression.
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Affiliation(s)
- Ilya Borovok
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv 69978, Israel
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48
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Gov Y, Borovok I, Korem M, Singh VK, Jayaswal RK, Wilkinson BJ, Rich SM, Balaban N. Quorum Sensing in Staphylococci Is Regulated via Phosphorylation of Three Conserved Histidine Residues. J Biol Chem 2004; 279:14665-72. [PMID: 14726534 DOI: 10.1074/jbc.m311106200] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Staphylococcus aureus cause infections by producing toxins, a process regulated by cell-cell communication (quorum sensing) through the histidine-phosphorylation of the target of RNAIII-activating protein (TRAP). We show here that TRAP is highly conserved in staphylococci and contains three completely conserved histidine residues (His-66, His-79, His-154) that are phosphorylated and essential for its activity. This was tested by constructing a TRAP(-) strain with each of the conserved histidine residues changed to alanine by site-directed mutagenesis. All mutants were tested for pathogenesis in vitro (expression of RNAIII and hemolytic activity) and in vivo (murine cellulitis model). Results show that RNAIII is not expressed in the TRAP(-) strain, that it is non hemolytic, and that it does not cause disease in vivo. These pathogenic phenotypes could be rescued in the strain containing the recovered traP, confirming the importance of TRAP in S. aureus pathogenesis. The phosphorylation of TRAP mutated in any of the conserved histidine residues was significantly reduced, and mutants defective in any one of these residues were non-pathogenic in vitro or in vivo, whereas those mutated in a non-conserved histidine residue (His-124) were as pathogenic as the wild type. These results confirm the importance of the three conserved histidine residues in TRAP activity. The phosphorylation pattern, structure, and gene organization of TRAP deviates from signaling molecules known to date, suggesting that TRAP belongs to a novel class of signal transducers.
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Affiliation(s)
- Yael Gov
- Department of Human Microbiology, Sackler School of Medicine, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
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49
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Uziel O, Borovok I, Schreiber R, Cohen G, Aharonowitz Y. Transcriptional regulation of the Staphylococcus aureus thioredoxin and thioredoxin reductase genes in response to oxygen and disulfide stress. J Bacteriol 2004; 186:326-34. [PMID: 14702300 PMCID: PMC305758 DOI: 10.1128/jb.186.2.326-334.2004] [Citation(s) in RCA: 108] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In this report we describe the cloning, organization, and promoter analysis of the Staphylococcus aureus thioredoxin (trxA) and thioredoxin reductase (trxB) genes and their transcription in response to changes in oxygen concentration and to oxidative stress compounds. Northern analysis showed that the S. aureus trxA and trxB genes were transcribed equally well in aerobic and anaerobic conditions. Several oxidative stress compounds were found to rapidly induce transcription of the trxA and trxB genes. The most pronounced effects were seen with diamide, a thiol-specific oxidant that promotes disulfide bond formation; menadione, a redox cycling agent; and tau-butyl hydroperoxide, an organic peroxide. In each case the induction was independent of the general stress sigma factor sigma(B). These studies show that the S. aureus trxA and trxB genes are upregulated following exposure to these oxidative stress agents, resulting in increased disulfide bond formation. In contrast, no effect of hydrogen peroxide on induction of the trxA and trxB genes was seen. We also show that the S. aureus thioredoxin reductase appears to be essential for growth. This observation, coupled with structural differences between the bacterial and mammalian thioredoxin reductases, suggests that it may serve as a target for the development of new antimicrobials.
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Affiliation(s)
- Orit Uziel
- Department of Molecular Microbiology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Israel
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50
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Abstract
Staphylococcus aureus are Gram-positive bacteria and cause diverse serious diseases in humans and animals through the production of toxins. The production of toxins is regulated by quorum sensing mechanisms, where proteins such as RNAIII activating protein (RAP) are secreted by the bacteria and induce virulence. Antibodies to RAP have been shown to protect mice from infection, but the molecular structure of RAP was not known and hindered vaccine development. To characterize RAP, recombinant protein was made and tested for its ability to induce genes important for pathogenesis (agr). In addition, monoclonal antibodies were produced to identify its cellular localization. Results shown here indicate that RAP is a 277-aa protein that is an ortholog of the ribosomal protein L2. Like the native molecule, recombinant RAP activates the production of RNAIII (encoded by agr). Using RAP specific monoclonal antibodies we demonstrate that RAP is continuously secreted and while RAP is expressed also in other bacteria (like Staphylococcus epidermidis, Staphylococcus xylosus and Escherichia coli), it is secreted to the culture medium only by S. aureus. Our results show that the ribosomal protein L2 has an extraribosomal function and that when secreted RAP acts as an autoinducer of virulence to regulate S. aureus pathogenesis.
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Affiliation(s)
- Moshe Korem
- Department of Human Microbiology, Sackler School of Medicine, Tel Aviv University, Israel
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