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Xu S, Liu Z, Ren P, Liu Y, Xiao F, Li W. BmfR, a novel GntR family regulator, regulates biofilm formation in marine-derived, Bacillus methylotrophicus B-9987. Microbiol Res 2024; 287:127859. [PMID: 39098095 DOI: 10.1016/j.micres.2024.127859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2024] [Revised: 07/21/2024] [Accepted: 07/24/2024] [Indexed: 08/06/2024]
Abstract
Biofilms are common living states for microorganisms, allowing them to adapt to environmental changes. Numerous Bacillus strains can form complex biofilms that play crucial roles in biocontrol processes. However, our current understanding of the molecular mechanisms of biofilm formation in Bacillus is mainly based on studies of Bacillus subtilis. Knowledge regarding the biofilm formation of other Bacillus species remains limited. In this study, we identified a novel transcriptional regulator, BmfR, belonging to the GntR family, that regulates biofilm formation in marine-derived Bacillus methylotrophicus B-9987. We demonstrated that BmfR induces biofilm formation by activating the extracellular polysaccharide structural genes epsA-O and negatively regulating the matrix gene repressor, SinR; of note it positively affects the expression of the master regulator of sporulation, Spo0A. Furthermore, database mining for BmfR homologs has revealed their widespread distribution among many bacterial species, mainly Firmicutes and Proteobacteria. This study advances our understanding of the biofilm regulatory network of Bacillus strains, and provides a new target for exploiting and manipulating biofilm formation.
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Affiliation(s)
- Shanshan Xu
- Key Laboratory of Marine Drugs, Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China
| | - Zengzhi Liu
- Key Laboratory of Marine Drugs, Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China
| | - Pengfei Ren
- Key Laboratory of Marine Drugs, Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China
| | - Yang Liu
- Key Laboratory of Marine Drugs, Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China
| | - Fei Xiao
- Key Laboratory of Marine Drugs, Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China
| | - Wenli Li
- Key Laboratory of Marine Drugs, Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China; Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; State Key Laboratory for Crop Stress Resistance and High-Efficiency Production, Shaanxi Key Laboratory of Natural Products & Chemical Biology, College of Chemistry & Pharmacy, Northwest A&F University, Yangling, Shannxi 712100, China.
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2
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Bianco CM, Caballero-Rothar NN, Ma X, Farley KR, Vanderpool CK. Transcriptional and post-transcriptional mechanisms modulate cyclopropane fatty acid synthase through small RNAs in Escherichia coli. J Bacteriol 2024; 206:e0004924. [PMID: 38980083 PMCID: PMC11340327 DOI: 10.1128/jb.00049-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2024] [Accepted: 06/12/2024] [Indexed: 07/10/2024] Open
Abstract
The small RNA (sRNA) RydC strongly activates cfa, which encodes the cyclopropane fatty acid synthase. Previous work demonstrated that RydC activation of cfa increases the conversion of unsaturated fatty acids to cyclopropanated fatty acids in membrane lipids and changes the biophysical properties of membranes, making cells more resistant to acid stress. The regulators that control RydC synthesis had not previously been identified. In this study, we identify a GntR-family transcription factor, YieP, that represses rydC transcription. YieP positively autoregulates its own transcription and indirectly regulates cfa through RydC. We further identify additional sRNA regulatory inputs that contribute to the control of RydC and cfa. The translation of yieP is repressed by the Fnr-dependent sRNA, FnrS, making FnrS an indirect activator of rydC and cfa. Conversely, RydC activity on cfa is antagonized by the OmpR-dependent sRNA OmrB. Altogether, this work illuminates a complex regulatory network involving transcriptional and post-transcriptional inputs that link the control of membrane biophysical properties to multiple environmental signals. IMPORTANCE Bacteria experience many environmental stresses that challenge their membrane integrity. To withstand these challenges, bacteria sense what stress is occurring and mount a response that protects membranes. Previous work documented the important roles of small RNA (sRNA) regulators in membrane stress responses. One sRNA, RydC, helps cells cope with membrane-disrupting stresses by promoting changes in the types of lipids incorporated into membranes. In this study, we identified a regulator, YieP, that controls when RydC is produced and additional sRNA regulators that modulate YieP levels and RydC activity. These findings illuminate a complex regulatory network that helps bacteria sense and respond to membrane stress.
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Affiliation(s)
- Colleen M. Bianco
- Department of Microbiology, University of Illinois, Urbana, Illinois, USA
| | | | - Xiangqian Ma
- Department of Microbiology, University of Illinois, Urbana, Illinois, USA
| | - Kristen R. Farley
- Department of Microbiology, University of Illinois, Urbana, Illinois, USA
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3
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Zhang T, Ji S, Zhang M, Wu F, Li X, Luo X, Huang Q, Li M, Zhang Y, Lu R. Effect of capsular polysaccharide phase variation on biofilm formation, motility and gene expression in Vibrio vulnificus. Gut Pathog 2024; 16:40. [PMID: 39075606 PMCID: PMC11287873 DOI: 10.1186/s13099-024-00620-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Accepted: 05/25/2024] [Indexed: 07/31/2024] Open
Abstract
Vibrio vulnificus, a significant marine pathogen, undergoes opaque (Op)-translucent (Tr) colony switching based on whether capsular polysaccharide (CPS) is produced. CPS phase variation is sometime accompanied by genetic variation or down-regulation of particular genes, such as wzb. In addition, CPS prevents biofilm formation and is important to the virulence of V. vulnificus. However, the extent to which there is a difference in gene expression between Tr and Op colonies and the impact of CPS phase variation on other behaviors of V. vulnificus remain unknown. In this work, the data have shown that CPS phase variation of V. vulnificus is affected by incubation time. Tr and Op strains exhibited similar growth rates. However, Tr strains had enhanced biofilm formation capacities but reduced swimming motility compared to Op strains. The RNA-seq assay revealed 488 differentially expressed genes, with 214 downregulated and 274 upregulated genes, between Tr and Op colonies. Genes associated with Tad pili and CPS were downregulated, whereas those involved in flagellum were upregulated, in Tr colonies compared with Op colonies. In addition, 9 putative c-di-GMP metabolism-associated genes and 28 genes encoding putative regulators were significantly differentially expressed, suggesting that CPS phase variation is probably strictly regulated in V. vulnificus. Moreover, 8 genes encoding putative porins were also differentially expressed between the two phenotypic colonies, indicating that bacterial outer membrane was remodeled during CPS phase variation. In brief, this work highlighted the gene expression profiles associated with CPS phase variation, but more studies should be performed to disclose the intrinsic mechanisms in the future.
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Affiliation(s)
- Tingting Zhang
- Department of Clinical Laboratory, Nantong Third People's Hospital, Affiliated Nantong Hospital 3 of Nantong University, Nantong, Jiangsu, 226006, China
- School of Medicine, Nantong University, Nantong, Jiangsu, 226019, China
| | - Shenjie Ji
- Department of Clinical Laboratory, Qidong People's Hospital, Qidong, Jiangsu, 226200, China
| | - Miaomiao Zhang
- Department of Clinical Laboratory, Nantong Third People's Hospital, Affiliated Nantong Hospital 3 of Nantong University, Nantong, Jiangsu, 226006, China
| | - Fei Wu
- Department of Clinical Laboratory, Nantong Third People's Hospital, Affiliated Nantong Hospital 3 of Nantong University, Nantong, Jiangsu, 226006, China
| | - Xue Li
- Department of Clinical Laboratory, Nantong Third People's Hospital, Affiliated Nantong Hospital 3 of Nantong University, Nantong, Jiangsu, 226006, China
| | - Xi Luo
- Department of Clinical Laboratory, Nantong Third People's Hospital, Affiliated Nantong Hospital 3 of Nantong University, Nantong, Jiangsu, 226006, China
| | - Qinglian Huang
- Department of Clinical Laboratory, Nantong Third People's Hospital, Affiliated Nantong Hospital 3 of Nantong University, Nantong, Jiangsu, 226006, China
- School of Medicine, Nantong University, Nantong, Jiangsu, 226019, China
- Department of Clinical Laboratory, Qidong People's Hospital, Qidong, Jiangsu, 226200, China
| | - Min Li
- Department of Gastroenterology and Clinical Laboratory, Nantong Third People's Hospital, Affiliated Nantong Hospital 3 of Nantong University, Nantong, Jiangsu, 226006, China
| | - Yiquan Zhang
- Department of Clinical Laboratory, Nantong Third People's Hospital, Affiliated Nantong Hospital 3 of Nantong University, Nantong, Jiangsu, 226006, China.
| | - Renfei Lu
- Department of Clinical Laboratory, Nantong Third People's Hospital, Affiliated Nantong Hospital 3 of Nantong University, Nantong, Jiangsu, 226006, China.
- School of Medicine, Nantong University, Nantong, Jiangsu, 226019, China.
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Vockenhuber MP, Hoetzel J, Maurer LM, Fröhlich P, Weiler S, Muller YA, Koeppl H, Suess B. A Novel RNA Aptamer as Synthetic Inducer of DasR Controlled Transcription. ACS Synth Biol 2024; 13:319-327. [PMID: 38127784 DOI: 10.1021/acssynbio.3c00553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2023]
Abstract
Progress in the synthetic biology field is driven by the development of new tools for synthetic circuit engineering. Traditionally, the focus has relied on protein-based designs. In recent years, the use of RNA-based tools has tremendously increased, due to their versatile functionality and applicability. A promising class of molecules is RNA aptamers, small, single-stranded RNA molecules that bind to a target molecule with high affinity and specificity. When targeting bacterial repressors, RNA aptamers allow one to add a new layer to an established protein-based regulation. In the present study, we selected an RNA aptamer binding the bacterial repressor DasR, preventing its binding to its operator sequence and activating DasR-controlled transcription in vivo. This was made possible only by the combination of an in vitro selection and subsequent in vivo screening. Next-generation sequencing of the selection process proved the importance of the in vivo screening for the discovery of aptamers functioning in the cell. Mutational and biochemical studies led to the identification of the minimal necessary binding motif. Taken together, the resulting combination of bacterial repressor and RNA aptamer enlarges the synthetic biology toolbox by adding a new level of regulation.
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Affiliation(s)
- Michael-Paul Vockenhuber
- Department of Biology, Technische Universität Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
- Center for Synthetic Microbiology (SYNMIKRO), Philipps-Universität Marburg, Karl-von-Frisch-Strasse 14, 35043 Marburg, Germany
| | - Janis Hoetzel
- Department of Biology, Technische Universität Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
| | - Lisa-Marie Maurer
- Department of Biology, Technische Universität Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
| | - Philipp Fröhlich
- Department of Electrical Engineering and Information Technology, Technische Universität Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
| | - Sigrid Weiler
- Lehrstuhl für Biotechnik, Department of Biology, Friedrich-Alexander University Erlangen-Nürnberg, Henkestr. 91, 91052 Erlangen, Germany
| | - Yves A Muller
- Lehrstuhl für Biotechnik, Department of Biology, Friedrich-Alexander University Erlangen-Nürnberg, Henkestr. 91, 91052 Erlangen, Germany
| | - Heinz Koeppl
- Department of Electrical Engineering and Information Technology, Technische Universität Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
- Centre for Synthetic Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| | - Beatrix Suess
- Department of Biology, Technische Universität Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
- Centre for Synthetic Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany
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5
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Meireles D, Pombinho R, Cabanes D. Signals behind Listeria monocytogenes virulence mechanisms. Gut Microbes 2024; 16:2369564. [PMID: 38979800 PMCID: PMC11236296 DOI: 10.1080/19490976.2024.2369564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Accepted: 06/13/2024] [Indexed: 07/10/2024] Open
Abstract
The tight and coordinated regulation of virulence gene expression is crucial to ensure the survival and persistence of bacterial pathogens in different contexts within their hosts. Considering this, bacteria do not express virulence factors homogenously in time and space, either due to their associated fitness cost or to their detrimental effect at specific infection stages. To efficiently infect and persist into their hosts, bacteria have thus to monitor environmental cues or chemical cell-to-cell signaling mechanisms that allow their transition from the external environment to the host, and therefore adjust gene expression levels, intrinsic biological activities, and appropriate behaviors. Listeria monocytogenes (Lm), a major Gram-positive facultative intracellular pathogen, stands out for its adaptability and capacity to thrive in a wide range of environments. Because of that, Lm presents itself as a significant concern in food safety and public health, that can lead to potentially life-threatening infections in humans. A deeper understanding of the intricate bacterial virulence mechanisms and the signals that control them provide valuable insights into the dynamic interplay between Lm and the host. Therefore, this review addresses the role of some crucial signals behind Lm pathogenic virulence mechanisms and explores how the ability to assimilate and interpret these signals is fundamental for pathogenesis, identifying potential targets for innovative antimicrobial strategies.
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Affiliation(s)
- Diana Meireles
- Instituto de Investigação e Inovação em Saúde, Porto, Portugal
- Group of Molecular Microbiology, IBMC, Porto, Portugal
- Instituto de Ciências Biomédicas Abel Salazar – ICBAS, Porto, Portugal
| | - Rita Pombinho
- Instituto de Investigação e Inovação em Saúde, Porto, Portugal
- Group of Molecular Microbiology, IBMC, Porto, Portugal
| | - Didier Cabanes
- Instituto de Investigação e Inovação em Saúde, Porto, Portugal
- Group of Molecular Microbiology, IBMC, Porto, Portugal
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Lassak J, Aveta EF, Vougioukas P, Hellwig M. Non-canonical food sources: bacterial metabolism of Maillard reaction products and its regulation. Curr Opin Microbiol 2023; 76:102393. [PMID: 37844449 DOI: 10.1016/j.mib.2023.102393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 09/05/2023] [Accepted: 09/08/2023] [Indexed: 10/18/2023]
Abstract
Proteins are an important part of our regular diet. During food processing, their amino acid composition can be chemically altered by the reaction of free amino groups with sugars - a process termed glycation. The resulting Maillard reaction products (MRPs) have low bioavailability and thus predominantly end up in the colon where they encounter our gut microbiota. In the following review, we summarize bacterial strategies to efficiently metabolize these non-canonical amino acids. A particular focus will be on the complex regulatory mechanisms that allow a tightly controlled expression of metabolic genes to successfully occupy the ecological niches that result from the chemical diversity of MRPs.
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Affiliation(s)
- Jürgen Lassak
- Fakultät für Biologie, Lehrstuhl Mikrobiologie/AG Mikrobielle Biochemie, Ludwig-Maximilians-Universität München, Großhaderner Str. 2, D-82152 Planegg-Martinsried, Germany.
| | - Erica F Aveta
- Fakultät für Biologie, Lehrstuhl Mikrobiologie/AG Mikrobielle Biochemie, Ludwig-Maximilians-Universität München, Großhaderner Str. 2, D-82152 Planegg-Martinsried, Germany
| | - Patroklos Vougioukas
- Fakultät Chemie und Lebensmittelchemie, Professur für Spezielle Lebensmittelchemie, Technische Universität Dresden, Bergstraße 66, D-01062 Dresden, Germany
| | - Michael Hellwig
- Fakultät Chemie und Lebensmittelchemie, Professur für Spezielle Lebensmittelchemie, Technische Universität Dresden, Bergstraße 66, D-01062 Dresden, Germany.
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Wang R, Zhao J, Chen L, Ye J, Wu H, Zhang H. LcbR1, a newly identified GntR family regulator, represses lincomycin biosynthesis in Streptomyces lincolnensis. Appl Microbiol Biotechnol 2023; 107:7501-7514. [PMID: 37768348 DOI: 10.1007/s00253-023-12756-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 08/09/2023] [Accepted: 08/30/2023] [Indexed: 09/29/2023]
Abstract
The Actinomycetes Streptomyces lincolnensis is the producer of lincosamide-type antibiotic lincomycin, a widely utilized drug against Gram-positive bacteria and protozoans. In this work, through gene knockout, complementation, and overexpression experiments, we identified LcbR1 (SLINC_1595), a GntR family transcriptional regulator, as a repressor for lincomycin biosynthesis. Deletion of lcbR1 boosted lincomycin production by 3.8-fold, without obvious change in morphological development or cellular growth. The homologues of LcbR1 are widely distributed in Streptomyces. Heterologous expression of SCO1410 from Streptomyces coelicolor resulted in the reduction of lincomycin yield, implying that the function of LcbR1 is conserved across different species. Alignment among sequences upstream of lcbR1 and their homologues revealed a conserved 16-bp palindrome (-TTGAACGATCCTTCAA-), which was further proven to be the recognition motif of LcbR1 by electrophoretic mobility shift assays (EMSAs). Via this motif, LcbR1 suppressed the transcription of lcbR1 and SLINC_1596 sharing the same bi-directional promoter. SLINC_1596, one important target of LcbR1, exerted a positive effect on lincomycin production. As detected by quantitative real-time PCR (qRT-PCR) analyses, the expressions of all selected structural (lmbA, lmbC, lmbJ, lmbV, and lmbW), resistance (lmrA and lmrB) and regulatory genes (lmrC and lmbU) from lincomycin biosynthesis cluster were upregulated in deletion strain ΔlcbR1 at 48 h of fermentation, while the mRNA amounts of bldD, glnR, ramR, SLCG_Lrp, and SLCG_2919, previously characterized as the regulators on lincomycin production, were decreased in strain ΔlcbR1, although the regulatory effects of LcbR1 on the above differential expression genes seemed to be indirect. Besides, indicated by EMSAs, the expression of lcbR1 might be regulated by GlnR, SLCG_Lrp, and SLCG_2919, which shows the complexity of the regulatory network on lincomycin biosynthesis. KEY POINTS: • LcbR1 is a novel and conservative GntR family regulator regulating lincomycin production. • LcbR1 modulates the expressions of lcbR1 and SLINC_1596 through a palindromic motif. • GlnR, SLCG_Lrp, and SLCG_2919 can control the expression of lcbR1.
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Affiliation(s)
- Ruida Wang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China
- Department of Applied Biology, School of Biotechnology, East China University of Science and Technology, Shanghai, 200237, China
| | - Jiaqi Zhao
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China
- Department of Applied Biology, School of Biotechnology, East China University of Science and Technology, Shanghai, 200237, China
| | - Lei Chen
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China
- Department of Applied Biology, School of Biotechnology, East China University of Science and Technology, Shanghai, 200237, China
| | - Jiang Ye
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China.
- Department of Applied Biology, School of Biotechnology, East China University of Science and Technology, Shanghai, 200237, China.
| | - Haizhen Wu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China.
- Department of Applied Biology, School of Biotechnology, East China University of Science and Technology, Shanghai, 200237, China.
| | - Huizhan Zhang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China
- Department of Applied Biology, School of Biotechnology, East China University of Science and Technology, Shanghai, 200237, China
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Patil RS, Sharma S, Bhaskarwar AV, Nambiar S, Bhat NA, Koppolu MK, Bhukya H. TetR and OmpR family regulators in natural product biosynthesis and resistance. Proteins 2023. [PMID: 37874037 DOI: 10.1002/prot.26621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2023] [Revised: 08/30/2023] [Accepted: 10/06/2023] [Indexed: 10/25/2023]
Abstract
This article provides a comprehensive review and sequence-structure analysis of transcription regulator (TR) families, TetR and OmpR/PhoB, involved in specialized secondary metabolite (SSM) biosynthesis and resistance. Transcription regulation is a fundamental process, playing a crucial role in orchestrating gene expression to confer a survival advantage in response to frequent environmental stress conditions. This process, coupled with signal sensing, enables bacteria to respond to a diverse range of intra and extracellular signals. Thus, major bacterial signaling systems use a receptor domain to sense chemical stimuli along with an output domain responsible for transcription regulation through DNA-binding. Sensory and output domains on a single polypeptide chain (one component system, OCS) allow response to stimuli by allostery, that is, DNA-binding affinity modulation upon signal presence/absence. On the other hand, two component systems (TCSs) allow cross-talk between the sensory and output domains as they are disjoint and transmit information by phosphorelay to mount a response. In both cases, however, TRs play a central role. Biosynthesis of SSMs, which includes antibiotics, is heavily regulated by TRs as it diverts the cell's resources towards the production of these expendable compounds, which also have clinical applications. These TRs have evolved to relay information across specific signals and target genes, thus providing a rich source of unique mechanisms to explore towards addressing the rapid escalation in antimicrobial resistance (AMR). Here, we focus on the TetR and OmpR family TRs, which belong to OCS and TCS, respectively. These TR families are well-known examples of regulators in secondary metabolism and are ubiquitous across different bacteria, as they also participate in a myriad of cellular processes apart from SSM biosynthesis and resistance. As a result, these families exhibit higher sequence divergence, which is also evident from our bioinformatic analysis of 158 389 and 77 437 sequences from TetR and OmpR family TRs, respectively. The analysis of both sequence and structure allowed us to identify novel motifs in addition to the known motifs responsible for TR function and its structural integrity. Understanding the diverse mechanisms employed by these TRs is essential for unraveling the biosynthesis of SSMs. This can also help exploit their regulatory role in biosynthesis for significant pharmaceutical, agricultural, and industrial applications.
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Affiliation(s)
- Rachit S Patil
- Department of Biology, Indian Institute of Science Education and Research, Tirupati, India
| | - Siddhant Sharma
- Department of Biology, Indian Institute of Science Education and Research, Tirupati, India
| | - Aditya V Bhaskarwar
- Department of Biology, Indian Institute of Science Education and Research, Tirupati, India
| | - Souparnika Nambiar
- Department of Biology, Indian Institute of Science Education and Research, Tirupati, India
| | - Niharika A Bhat
- Department of Biology, Indian Institute of Science Education and Research, Tirupati, India
| | - Mani Kanta Koppolu
- Department of Biology, Indian Institute of Science Education and Research, Tirupati, India
| | - Hussain Bhukya
- Department of Biology, Indian Institute of Science Education and Research, Tirupati, India
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Li JY, Liang JY, Liu ZY, Yi YZ, Zhao J, Huang ZY, Chen J. Multicopy Chromosome Integration and Deletion of Negative Global Regulators Significantly Increased the Heterologous Production of Aborycin in Streptomyces coelicolor. Mar Drugs 2023; 21:534. [PMID: 37888469 PMCID: PMC10608281 DOI: 10.3390/md21100534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 10/10/2023] [Accepted: 10/11/2023] [Indexed: 10/28/2023] Open
Abstract
Aborycin is a type I lasso peptide with a stable interlocked structure, offering a favorable framework for drug development. The aborycin biosynthetic gene cluster gul from marine sponge-associated Streptomyces sp. HNS054 was cloned and integrated into the chromosome of S. coelicolor hosts with different copies. The three-copy gul-integration strain S. coelicolor M1346::3gul showed superior production compared to the one-copy or two-copy gul-integration strains, and the total titer reached approximately 10.4 mg/L, i.e., 2.1 times that of the native strain. Then, five regulatory genes, phoU (SCO4228), wblA (SCO3579), SCO1712, orrA (SCO3008) and gntR (SCO1678), which reportedly have negative effects on secondary metabolism, were further knocked out from the M1346::3gul genome by CRISPR/Cas9 technology. While the ΔSCO1712 mutant showed a significant decrease (4.6 mg/L) and the ΔphoU mutant showed no significant improvement (12.1 mg/L) in aborycin production, the ΔwblA, ΔorrA and ΔgntR mutations significantly improved the aborycin titers to approximately 23.6 mg/L, 56.3 mg/L and 48.2 mg/L, respectively, which were among the highest heterologous yields for lasso peptides in both Escherichia coli systems and Streptomyces systems. Thus, this study provides important clues for future studies on enhancing antibiotic production in Streptomyces systems.
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Affiliation(s)
- Jia-Yi Li
- Department of Marine Biological Science & Technology, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China; (J.-Y.L.); (J.-Y.L.); (Z.-Y.L.); (Y.-Z.Y.); (J.Z.)
| | - Jun-Yu Liang
- Department of Marine Biological Science & Technology, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China; (J.-Y.L.); (J.-Y.L.); (Z.-Y.L.); (Y.-Z.Y.); (J.Z.)
| | - Zhao-Yuan Liu
- Department of Marine Biological Science & Technology, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China; (J.-Y.L.); (J.-Y.L.); (Z.-Y.L.); (Y.-Z.Y.); (J.Z.)
| | - Yue-Zhao Yi
- Department of Marine Biological Science & Technology, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China; (J.-Y.L.); (J.-Y.L.); (Z.-Y.L.); (Y.-Z.Y.); (J.Z.)
| | - Jing Zhao
- Department of Marine Biological Science & Technology, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China; (J.-Y.L.); (J.-Y.L.); (Z.-Y.L.); (Y.-Z.Y.); (J.Z.)
- State-Province Joint Engineering Laboratory of Marine Bioproducts and Technology, Xiamen University, Xiamen 361102, China
- Xiamen City Key Laboratory of Urban Sea Ecological Conservation and Restoration, Xiamen University, Xiamen 361102, China
| | - Zhi-Yong Huang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
| | - Jun Chen
- Department of Marine Biological Science & Technology, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China; (J.-Y.L.); (J.-Y.L.); (Z.-Y.L.); (Y.-Z.Y.); (J.Z.)
- State-Province Joint Engineering Laboratory of Marine Bioproducts and Technology, Xiamen University, Xiamen 361102, China
- Xiamen City Key Laboratory of Urban Sea Ecological Conservation and Restoration, Xiamen University, Xiamen 361102, China
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10
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Wang R, Zhao J, Chen L, Ye J, Wu H, Zhang H. LcbR1, a newly identified GntR family regulator, represses lincomycin biosynthesis in Streptomyces lincolnensis. Appl Microbiol Biotechnol 2023. [DOI: doi.org/10.1007/s00253-023-12756-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 08/09/2023] [Accepted: 08/30/2023] [Indexed: 10/09/2023]
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Chauhan NK, Anand A, Sharma A, Dhiman K, Gosain TP, Singh P, Singh P, Khan E, Chattopadhyay G, Kumar A, Sharma D, Ashish, Sharma TK, Singh R. Structural and Functional Characterization of Rv0792c from Mycobacterium tuberculosis: Identifying Small Molecule Inhibitor against HutC Protein. Microbiol Spectr 2023; 11:e0197322. [PMID: 36507689 PMCID: PMC9927256 DOI: 10.1128/spectrum.01973-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
In order to adapt in host tissues, microbial pathogens regulate their gene expression through a variety of transcription factors. Here, we have functionally characterized Rv0792c, a HutC homolog from Mycobacterium tuberculosis. In comparison to the parental strain, a strain of M. tuberculosis with a Rv0792c mutant was compromised for survival upon exposure to oxidative stress and infection in guinea pigs. RNA sequencing analysis revealed that Rv0792c regulates the expression of genes involved in stress adaptation and virulence of M. tuberculosis. Solution small-angle X-ray scattering (SAXS) data-steered model building confirmed that the C-terminal region plays a pivotal role in dimer formation. Systematic evolution of ligands by exponential enrichment (SELEX) resulted in the identification of single-strand DNA (ssDNA) aptamers that can be used as a tool to identify small-molecule inhibitors targeting Rv0792c. Using SELEX and SAXS data-based modeling, we identified residues essential for Rv0792c's aptamer binding activity. In this study, we also identified I-OMe-Tyrphostin as an inhibitor of Rv0792c's aptamer and DNA binding activity. The identified small molecule reduced the growth of intracellular M. tuberculosis in macrophages. The present study thus provides a detailed shape-function characterization of a HutC family of transcription factor from M. tuberculosis. IMPORTANCE Prokaryotes encode a large number of GntR family transcription factors that are involved in various fundamental biological processes, including stress adaptation and pathogenesis. Here, we investigated the structural and functional role of Rv0792c, a HutC homolog from M. tuberculosis. We demonstrated that Rv0792c is essential for M. tuberculosis to adapt to oxidative stress and establish disease in guinea pigs. Using a systematic evolution of ligands by exponential enrichment (SELEX) approach, we identified ssDNA aptamers from a random ssDNA library that bound to Rv0792c protein. These aptamers were thoroughly characterized using biochemical and biophysical assays. Using SAXS, we determined the structural model of Rv0792c in both the presence and absence of the aptamers. Further, using a combination of SELEX and SAXS methodologies, we identified I-OMe-Tyrphostin as a potential inhibitor of Rv0792c. Here we provide a detailed functional characterization of a transcription factor belonging to the HutC family from M. tuberculosis.
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Affiliation(s)
- Neeraj Kumar Chauhan
- Translational Health Science and Technology Institutegrid.464764.3, Faridabad, Haryana, India
| | - Anjali Anand
- Translational Health Science and Technology Institutegrid.464764.3, Faridabad, Haryana, India
| | - Arun Sharma
- Translational Health Science and Technology Institutegrid.464764.3, Faridabad, Haryana, India
| | - Kanika Dhiman
- Institute of Microbial Technologygrid.417641.1, Council of Scientific and Industrial Research, Chandigarh, India
| | - Tannu Priya Gosain
- Translational Health Science and Technology Institutegrid.464764.3, Faridabad, Haryana, India
| | - Prashant Singh
- Institute of Microbial Technologygrid.417641.1, Council of Scientific and Industrial Research, Chandigarh, India
| | - Padam Singh
- Translational Health Science and Technology Institutegrid.464764.3, Faridabad, Haryana, India
| | - Eshan Khan
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indoregrid.450280.b, Indore, India
| | | | - Amit Kumar
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indoregrid.450280.b, Indore, India
| | - Deepak Sharma
- Institute of Microbial Technologygrid.417641.1, Council of Scientific and Industrial Research, Chandigarh, India
| | - Ashish
- Institute of Microbial Technologygrid.417641.1, Council of Scientific and Industrial Research, Chandigarh, India
| | - Tarun Kumar Sharma
- Translational Health Science and Technology Institutegrid.464764.3, Faridabad, Haryana, India
| | - Ramandeep Singh
- Translational Health Science and Technology Institutegrid.464764.3, Faridabad, Haryana, India
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Shao Y, Tang G, Huang Y, Ke W, Wang S, Zheng D, Ruan L. Transcriptional regulator Sar regulates the multiple secretion systems in Xanthomonas oryzae. MOLECULAR PLANT PATHOLOGY 2023; 24:16-27. [PMID: 36177860 PMCID: PMC9742495 DOI: 10.1111/mpp.13272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Revised: 08/24/2022] [Accepted: 08/24/2022] [Indexed: 06/16/2023]
Abstract
Xanthomonas oryzae pv. oryzae (Xoo) is a notorious plant pathogen that causes leaf blight of rice cultivars. The pathogenic bacteria possess numerous transcriptional regulators to regulate various biological processes, such as pathogenicity in the host plant. Our previous study identified a new master regulator PXO_RS20790 that is involved in pathogenicity for Xoo against the host rice. However, the molecular functions of PXO_RS20790 are still unclear. Here, we demonstrate that transcriptional regulator Sar (PXO_RS20790) regulates multiple secretion systems. The RNA-sequencing analysis, bacterial one-hybrid assay, and electrophoretic mobility shift assay revealed that Sar enables binding of the promoters of the T1SS-related genes, the avirulence gene, raxX, and positively regulates these genes' expression. Meanwhile, we found that Sar positively regulated the T6SS-1 clusters but did not regulate the T6SS-2 clusters. Furthermore, we revealed that only T6SS-2 is involved in interbacterial competition. We also indicated that Sar could bind the promoters of the T3SS regulators, hrpG and hrpX, to activate these two genes' transcription. Our findings revealed that Sar is a crucial regulator of multiple secretion systems and virulence.
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Affiliation(s)
- Yanan Shao
- State Key Laboratory of Agricultural Microbiology, College of Life Science and TechnologyHuazhong Agricultural UniversityWuhanChina
| | - Guiyu Tang
- State Key Laboratory of Agricultural Microbiology, College of Life Science and TechnologyHuazhong Agricultural UniversityWuhanChina
| | - Yuanyuan Huang
- State Key Laboratory of Agricultural Microbiology, College of Life Science and TechnologyHuazhong Agricultural UniversityWuhanChina
| | - Wenli Ke
- State Key Laboratory of Agricultural Microbiology, College of Life Science and TechnologyHuazhong Agricultural UniversityWuhanChina
| | - Shasha Wang
- State Key Laboratory of Agricultural Microbiology, College of Life Science and TechnologyHuazhong Agricultural UniversityWuhanChina
| | - Dehong Zheng
- State Key Laboratory of Agricultural Microbiology, College of Life Science and TechnologyHuazhong Agricultural UniversityWuhanChina
- National Demonstration Center for Experimental Plant Science Education, College of AgricultureGuangxi UniversityNanningChina
| | - Lifang Ruan
- State Key Laboratory of Agricultural Microbiology, College of Life Science and TechnologyHuazhong Agricultural UniversityWuhanChina
- College of Resources and EnvironmentTibet Agriculture & Animal Husbandry UniversityLinzhiChina
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Castrejón-Godínez ML, Tovar-Sánchez E, Ortiz-Hernández ML, Encarnación-Guevara S, Martínez-Batallar ÁG, Hernández-Ortiz M, Sánchez-Salinas E, Rodríguez A, Mussali-Galante P. Proteomic analysis of Burkholderia zhejiangensis CEIB S4-3 during the methyl parathion degradation process. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2022; 187:105197. [PMID: 36127069 DOI: 10.1016/j.pestbp.2022.105197] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 06/24/2022] [Accepted: 08/02/2022] [Indexed: 06/15/2023]
Abstract
Methyl parathion is an organophosphorus pesticide widely employed worldwide to control pests in agricultural and domestic environments. However, due to its intensive use, high toxicity, and environmental persistence, methyl parathion is recognized as an important ecosystem and human health threat, causing severe environmental pollution events and numerous human poisoning and deaths each year. Therefore, identifying and characterizing microorganisms capable of fully degrading methyl parathion and its degradation metabolites is a crucial environmental task for the bioremediation of pesticide-polluted sites. Burkholderia zhejiangensis CEIB S4-3 is a bacterial strain isolated from agricultural soils capable of immediately hydrolyzing methyl parathion at a concentration of 50 mg/L and degrading the 100% of the released p-nitrophenol in a 12-hour lapse when cultured in minimal salt medium. In this study, a comparative proteomic analysis was conducted in the presence and absence of methyl parathion to evaluate the biological mechanisms implicated in the methyl parathion biodegradation and resistance by the strain B. zhejiangensis CEIB S4-3. In each treatment, the changes in the protein expression patterns were evaluated at three sampling times, zero, three, and nine hours through the use of two-dimensional polyacrylamide gel electrophoresis (2D-PAGE), and the differentially expressed proteins were identified by mass spectrometry (MALDI-TOF). The proteomic analysis allowed the identification of 72 proteins with differential expression, 35 proteins in the absence of the pesticide, and 37 proteins in the experimental condition in the presence of methyl parathion. The identified proteins are involved in different metabolic processes such as the carbohydrate and amino acids metabolism, carbon metabolism and energy production, fatty acids β-oxidation, and the aromatic compounds catabolism, including enzymes of the both p-nitrophenol degradation pathways (Hydroquinone dioxygenase and Hydroxyquinol 1,2 dioxygenase), as well as the overexpression of proteins implicated in cellular damage defense mechanisms such as the response and protection of the oxidative stress, reactive oxygen species defense, detoxification of xenobiotics, and DNA repair processes. According to these data, B. zhejiangensis CEIB S4-3 overexpress different proteins related to aromatic compounds catabolism and with the p-nitrophenol degradation pathways, the higher expression levels observed in the two subunits of the enzyme Hydroquinone dioxygenase, suggest a preferential use of the Hydroquinone metabolic pathway in the p-nitrophenol degradation process. Moreover the overexpression of several proteins implicated in the oxidative stress response, xenobiotics detoxification, and DNA damage repair reveals the mechanisms employed by B. zhejiangensis CEIB S4-3 to counteract the adverse effects caused by the methyl parathion and p-nitrophenol exposure.
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Affiliation(s)
- María Luisa Castrejón-Godínez
- Facultad de Ciencias Biológicas, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, C.P. 62209 Cuernavaca, Morelos, Mexico
| | - Efraín Tovar-Sánchez
- Centro de Investigación en Biodiversidad y Conservación, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, C.P. 62209 Cuernavaca, Morelos, Mexico.
| | - Ma Laura Ortiz-Hernández
- Misión Sustentabilidad México A.C., Priv. Laureles 6, Col. Chamilpa, C.P. 62210 Cuernavaca, Morelos, Mexico
| | - Sergio Encarnación-Guevara
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Av. Universidad s/n, Col. Chamilpa, C.P. 62210 Cuernavaca, Morelos, Mexico
| | - Ángel Gabriel Martínez-Batallar
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Av. Universidad s/n, Col. Chamilpa, C.P. 62210 Cuernavaca, Morelos, Mexico
| | - Magdalena Hernández-Ortiz
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Av. Universidad s/n, Col. Chamilpa, C.P. 62210 Cuernavaca, Morelos, Mexico
| | - Enrique Sánchez-Salinas
- Misión Sustentabilidad México A.C., Priv. Laureles 6, Col. Chamilpa, C.P. 62210 Cuernavaca, Morelos, Mexico
| | - Alexis Rodríguez
- Centro de Investigación en Biotecnología, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, C.P. 62209 Cuernavaca, Morelos, Mexico.
| | - Patricia Mussali-Galante
- Centro de Investigación en Biotecnología, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, C.P. 62209 Cuernavaca, Morelos, Mexico.
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Weber M, Fuchs TM. Metabolism in the Niche: a Large-Scale Genome-Based Survey Reveals Inositol Utilization To Be Widespread among Soil, Commensal, and Pathogenic Bacteria. Microbiol Spectr 2022; 10:e0201322. [PMID: 35924911 PMCID: PMC9430895 DOI: 10.1128/spectrum.02013-22] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 07/22/2022] [Indexed: 11/20/2022] Open
Abstract
Phytate is the main phosphorus storage molecule of plants and is therefore present in large amounts in the environment and in the diet of humans and animals. Its dephosphorylated form, the polyol myo-inositol (MI), can be used by bacteria as a sole carbon and energy source. The biochemistry and regulation of MI degradation were deciphered in Bacillus subtilis and Salmonella enterica, but a systematic survey of this catabolic pathway has been missing until now. For a comprehensive overview of the distribution of MI utilization, we analyzed 193,757 bacterial genomes, representing a total of 24,812 species, for the presence, organization, and taxonomic prevalence of inositol catabolic gene clusters (IolCatGCs). The genetic capacity for MI degradation was detected in 7,384 (29.8%) of all species for which genome sequences were available. IolCatGC-positive species were particularly found among Actinobacteria and Proteobacteria and to a much lesser extent in Bacteroidetes. IolCatGCs are very diverse in terms of gene number and functions, whereas the order of core genes is highly conserved on the phylum level. We predict that 111 animal pathogens, more than 200 commensals, and 430 plant pathogens or rhizosphere bacteria utilize MI, underscoring that IolCatGCs provide a growth benefit within distinct ecological niches. IMPORTANCE This study reveals that the capacity to utilize inositol is unexpectedly widespread among soil, commensal, and pathogenic bacteria. We assume that this yet-neglected metabolism plays a pivotal role in the microbial turnover of phytate and inositols. The bioinformatic tool established here enables predicting to which extent and genetic variance a bacterial determinant is present in all genomes sequenced so far.
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Affiliation(s)
- Michael Weber
- Friedrich-Loeffler-Institut/Federal Research Institute for Animal Health, Institute of Molecular Pathogenesis, Jena, Germany
| | - Thilo M. Fuchs
- Friedrich-Loeffler-Institut/Federal Research Institute for Animal Health, Institute of Molecular Pathogenesis, Jena, Germany
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15
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Xia C, Zeng X, Peng L, Pan D, Wu Z, Guo Y, Cai Z. The function of uridine diphosphate glucose pyrophosphorylase in the lyophilization-stress response of Lactobacillus acidophilus. ANN MICROBIOL 2022. [DOI: 10.1186/s13213-022-01680-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Purpose
Uridine diphosphate glucose pyrophosphorylase (UGPase) plays an important role in glucose metabolism, catalyzing the reversible formation and decomposition of UDP-glucose (UDPG). In previous work, we found that UGPase is a key enzyme in lyophilization response for Lactobacillus acidophilus (L. acidophilus). However, its function and regulatory mechanism in the freeze-drying stress response are unknown. Herein, the effect of UGPase on freeze-drying survival rate of Staphylococcus carnosus (S. carnosus) was studied.
Methods
In this work, the genes LBA1719 encoding UGPase of L. acidophilus ATCC4356 were inserted into plasmid pMG-36e to construct the recombinant plasmid pMG-LBA1719 and then overexpressed in S. carnosus; the control group was S. carnosus transformed by pMG-36e. The lyophilization-survival rate of overexpressed S. carnosus was determined, and the differentially expressed genes (DEGs) were analyzed by transcriptome to disclose the mechanism of LBA1719 in regulating the lyophilization-survival rate.
Results
Compared with the control group, the UGPase activities of the overexpressed S. carnosus increased by 35.49%, while the lyophilization-survival rates decreased by 11.17% (p < 0.05). Overexpression of LBA1719 decreased the expression of genes gapA, gapB, and pgiA in carbohydrate metabolism and dapA, dapB, and dapE in amino acid metabolism, significantly changing the physiological characteristics of S. carnosus and decreasing its lyophilization-survival rate.
Conclusion
In summary, overexpression of UGPase accelerated the growth rate of S. carnosus and reduced its lyophilization-survival rates. GapA, gapB, pgiA, dapA, dapB, and dapE are vital to lyophilization protection in lactic acid bacteria (LAB). These findings provide new theoretical basis for analyzing the regulatory and molecular mechanisms of lyophilization resistance in LABs.
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Ali F, Kumar H, Patil S, Kotecha K, Banjar A, Daud A. Target-DBPPred: An intelligent model for prediction of DNA-binding proteins using discrete wavelet transform based compression and light eXtreme gradient boosting. Comput Biol Med 2022; 145:105533. [PMID: 35447463 DOI: 10.1016/j.compbiomed.2022.105533] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 04/11/2022] [Accepted: 04/13/2022] [Indexed: 11/03/2022]
Abstract
DNA-protein interaction is a critical biological process that performs influential activities, including DNA transcription and recombination. DBPs (DNA-binding proteins) are closely associated with different kinds of human diseases (asthma, cancer, and AIDS), while some of the DBPs are used in the production of antibiotics, steroids, and anti-inflammatories. Several methods have been reported for the prediction of DBPs. However, a more intelligent method is still highly desirable for the accurate prediction of DBPs. This study presents an intelligent computational method, Target-DBPPred, to improve DBPs prediction. Important features from primary protein sequences are investigated via a novel feature descriptor, called EDF-PSSM-DWT (Evolutionary difference formula position-specific scoring matrix-discrete wavelet transform) and several other multi-evolutionary methods, including F-PSSM (Filtered position-specific scoring matrix), EDF-PSSM (Evolutionary difference formula position-specific scoring matrix), PSSM-DPC (Position-specific scoring matrix-dipeptide composition), and Lead-BiPSSM (Lead-bigram-position specific scoring matrix) to encapsulate diverse multivariate features. The best feature set from the features of each descriptor is selected using sequential forward selection (SFS). Further, four models are trained using Adaboost, XGB (eXtreme gradient boosting), ERT (extremely randomized trees), and LiXGB (Light eXtreme gradient boosting) classifiers. LiXGB, with the best feature set of EDF-PSSM-DWT, has attained 6.69% and 15.07% higher performance in terms of accuracies using training and testing datasets, respectively. The obtained results verify the improved performance of our proposed predictor over the existing predictors.
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Affiliation(s)
- Farman Ali
- Department of Elementary and Secondary Education, Peshawar, Khyber Pakhtunkhwa, Pakistan; School of Computer Science and Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China.
| | - Harish Kumar
- Department of Computer Science, College of Computer Science, King Khalid University, Abha, Saudi Arabia
| | - Shruti Patil
- Symbiosis Institute of Technology, Symbiosis Centre for Applied Artificial Intelligence, Symbiosis International University, Pune, India
| | - Ketan Kotecha
- Symbiosis Institute of Technology, Symbiosis Centre for Applied Artificial Intelligence, Symbiosis International University, Pune, India.
| | - Ameen Banjar
- Department of Information Systems, College of Computer Science and Engineering, University of Jeddah, Jeddah, Saudi Arabia
| | - Ali Daud
- Key Laboratory of Oceanographic Big Data Mining & Application of Zhejiang Province, School of Information Engineering, Zhejiang Ocean University, Zhoushan, 316022, China; Department of Computer Science and Artificial Intelligence, University of Jeddah, Jeddah, Saudi Arabia.
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Transcriptional Regulation and Functional Characterization of the Plasmid-Borne oqxAB Genes in Salmonella Typhimurium. Microbiol Spectr 2022; 10:e0217021. [PMID: 35315694 PMCID: PMC9045139 DOI: 10.1128/spectrum.02170-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Coexistence of oqxAB and aac(6')-Ib-cr is often associated with the expression of fluoroquinolone resistance in Salmonella. The actual role of the plasmid-borne oqxAB gene and its regulatory mechanism compared to its chromosomally encoded counterpart in Klebsiella pneumoniae remain unclear We found that cloning of oqxAB gene only or chromosomally encoded oqxABR (ABRc) locus did not lead to an increase of ciprofloxacin (CIP) minimum inhibitory concentration (MIC) in S. Typhimurium, while cloning of the plasmid-encoded oqxABR (ABRp) locus led to a 4-fold increase in CIP MIC, reaching 0.0065 μg/mL. The co-carriage of these constructs with aac(6')-Ib-cr further increased the CIP MIC to 0.25 μg/mL in S. Typhimurium carrying aac(6')-Ib-cr and ABRp. Analysis of the transcription start site sequences showed that the expression level of suppressor protein gene, oqxR, in strains carrying ABRp was lower than that of its chromosomal counterpart due to the truncated promoter region in ABRp. The lower expression of OqxR in ABRp led to the overexpression of OqxAB, which elevated CIP MIC and exhibited a synergistic antimicrobial effect with the aac(6')-Ib-cr gene product to confer intermediate CIP (MIC = 0.25 μg/mL) in S. Typhimurium. Global transcriptional regulators in S. Typhimurium did not seem to play a role in regulating the plasmid-borne oqxAB genes. In conclusion, findings in this work showed that neither aac(6')-Ib-cr nor oqxABRp, but the combination of both genes, could mediate intermediated resistance to fluoroquinolone in Salmonella. The truncated promoter region in the oqxR gene of the plasmid-encoded locus led to the constituted expression of oqxAB genes. IMPORTANCE The transferable mechanisms of quinolone resistance (TMQR) gene, oqxAB, has been widely detected in Salmonella and is commonly associated with aac(6')-Ib-cr. It is thought to be associated with fluoroquinolone resistance, while its ancestor gene from K. pneumoniae is not. This study evaluated the actual role of the plasmid-borne oqxAB genes in Salmonella and showed that it was not able to mediate intermediated resistance to fluoroquinolone and only did so when it coexisted with aac(6')-Ib-cr. Chromosomally encoded oqxABRc from K. pneumoniae was not able to mediate enhanced CIP MIC due to tight regulation by the suppressor oqxR. However, plasmid-encoded oqxABRp enabled oqxAB to be expressed constitutionally due to the truncated promoter region of oqxR, leading to lower expression of the suppressor oqxR. This study clarified the roles of oqxAB and aac(6')-Ib-cr in mediating fluoroquinolone resistance in Salmonella and provides insights into the regulation of plasmid-encoded TMQR determinant, oqxAB.
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Lassak J, Sieber A, Hellwig M. Exceptionally versatile take II: post-translational modifications of lysine and their impact on bacterial physiology. Biol Chem 2022; 403:819-858. [PMID: 35172419 DOI: 10.1515/hsz-2021-0382] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 01/05/2022] [Indexed: 01/16/2023]
Abstract
Among the 22 proteinogenic amino acids, lysine sticks out due to its unparalleled chemical diversity of post-translational modifications. This results in a wide range of possibilities to influence protein function and hence modulate cellular physiology. Concomitantly, lysine derivatives form a metabolic reservoir that can confer selective advantages to those organisms that can utilize it. In this review, we provide examples of selected lysine modifications and describe their role in bacterial physiology.
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Affiliation(s)
- Jürgen Lassak
- Department of Biology I, Microbiology, Ludwig-Maximilians-Universität München, Großhaderner Straße 2-4, D-82152 Planegg, Germany
| | - Alina Sieber
- Department of Biology I, Microbiology, Ludwig-Maximilians-Universität München, Großhaderner Straße 2-4, D-82152 Planegg, Germany
| | - Michael Hellwig
- Technische Universität Braunschweig - Institute of Food Chemistry, Schleinitzstraße 20, D-38106 Braunschweig, Germany
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A High-Content Microscopy Screening Identifies New Genes Involved in Cell Width Control in Bacillus subtilis. mSystems 2021; 6:e0101721. [PMID: 34846166 PMCID: PMC8631317 DOI: 10.1128/msystems.01017-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
How cells control their shape and size is a fundamental question of biology. In most bacteria, cell shape is imposed by the peptidoglycan (PG) polymeric meshwork that surrounds the cell. Thus, bacterial cell morphogenesis results from the coordinated action of the proteins assembling and degrading the PG shell. Remarkably, during steady-state growth, most bacteria maintain a defined shape along generations, suggesting that error-proof mechanisms tightly control the process. In the rod-shaped model for the Gram-positive bacterium Bacillus subtilis, the average cell length varies as a function of the growth rate, but the cell diameter remains constant throughout the cell cycle and across growth conditions. Here, in an attempt to shed light on the cellular circuits controlling bacterial cell width, we developed a screen to identify genetic determinants of cell width in B. subtilis. Using high-content screening (HCS) fluorescence microscopy and semiautomated measurement of single-cell dimensions, we screened a library of ∼4,000 single knockout mutants. We identified 13 mutations significantly altering cell diameter, in genes that belong to several functional groups. In particular, our results indicate that metabolism plays a major role in cell width control in B. subtilis. IMPORTANCE Bacterial shape is primarily dictated by the external cell wall, a vital structure that, as such, is the target of countless antibiotics. Our understanding of how bacteria synthesize and maintain this structure is therefore a cardinal question for both basic and applied research. Bacteria usually multiply from generation to generation while maintaining their progenies with rigorously identical shapes. This implies that the bacterial cells constantly monitor and maintain a set of parameters to ensure this perpetuation. Here, our study uses a large-scale microscopy approach to identify at the whole-genome level, in a model bacterium, the genes involved in the control of one of the most tightly controlled cellular parameters, the cell width.
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Abeywickrama TD, Perera IC. In Silico Characterization and Virtual Screening of GntR/HutC Family Transcriptional Regulator MoyR: A Potential Monooxygenase Regulator in Mycobacterium tuberculosis. BIOLOGY 2021; 10:biology10121241. [PMID: 34943156 PMCID: PMC8698889 DOI: 10.3390/biology10121241] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 07/01/2021] [Accepted: 07/02/2021] [Indexed: 12/31/2022]
Abstract
Simple Summary In an era where the world faces new diseases and pathogens, another emerging challenge is neglected pathogens becoming more notorious. Transcriptional regulators play a vital role in the pathogenesis and survival of these pathogens. Hence, characterizing transcriptional regulators, either in vitro or in silico, is of great importance. Here, we present the first structural characterization of a GntR/HutC regulator in Mycobacterium tuberculosis via in silico methods. We have suggested its possible role and potential as a drug target as well as identified possible drug leads that can be used for further improvements. Abstract Mycobacterium tuberculosis is a well-known pathogen due to the emergence of drug resistance associated with it, where transcriptional regulators play a key role in infection, colonization and persistence. The genome of M. tuberculosis encodes many transcriptional regulators, and here we report an in-depth in silico characterization of a GntR regulator: MoyR, a possible monooxygenase regulator. Homology modelling provided a reliable structure for MoyR, showing homology with a HutC regulator DasR from Streptomyces coelicolor. In silico physicochemical analysis revealed that MoyR is a cytoplasmic protein with higher thermal stability and higher pI. Four highly probable binding pockets were determined in MoyR and the druggability was higher in the orthosteric binding site consisting of three conserved critical residues: TYR179, ARG223 and GLU234. Two highly conserved leucine residues were identified in the effector-binding region of MoyR and other HutC homologues, suggesting that these two residues can be crucial for structure stability and oligomerization. Virtual screening of drug leads resulted in four drug-like compounds with greater affinity to MoyR with potential inhibitory effects for MoyR. Our findings support that this regulator protein can be valuable as a therapeutic target that can be used for developing drug leads.
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21
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Bandera AM, Bartho J, Lammens K, Drexler DJ, Kleinschwärzer J, Hopfner KP, Witte G. BusR senses bipartite DNA binding motifs by a unique molecular ruler architecture. Nucleic Acids Res 2021; 49:10166-10177. [PMID: 34432045 PMCID: PMC8517857 DOI: 10.1093/nar/gkab736] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 07/27/2021] [Accepted: 08/12/2021] [Indexed: 12/18/2022] Open
Abstract
The cyclic dinucleotide second messenger c-di-AMP is a major player in regulation of potassium homeostasis and osmolyte transport in a variety of bacteria. Along with various direct interactions with proteins such as potassium channels, the second messenger also specifically binds to transcription factors, thereby altering the processes in the cell on the transcriptional level. We here describe the structural and biochemical characterization of BusR from the human pathogen Streptococcus agalactiae. BusR is a member of a yet structurally uncharacterized subfamily of the GntR family of transcription factors that downregulates transcription of the genes for the BusA (OpuA) glycine-betaine transporter upon c-di-AMP binding. We report crystal structures of full-length BusR, its apo and c-di-AMP bound effector domain, as well as cryo-EM structures of BusR bound to its operator DNA. Our structural data, supported by biochemical and biophysical data, reveal that BusR utilizes a unique domain assembly with a tetrameric coiled-coil in between the binding platforms, serving as a molecular ruler to specifically recognize a 22 bp separated bipartite binding motif. Binding of c-di-AMP to BusR induces a shift in equilibrium from an inactivated towards an activated state that allows BusR to bind the target DNA, leading to transcriptional repression.
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Affiliation(s)
- Adrian M Bandera
- Gene Center, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, D-81377 München, Germany.,Department of Biochemistry, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, D-81377 München, Germany
| | - Joseph Bartho
- Gene Center, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, D-81377 München, Germany.,Department of Biochemistry, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, D-81377 München, Germany
| | - Katja Lammens
- Gene Center, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, D-81377 München, Germany.,Department of Biochemistry, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, D-81377 München, Germany
| | - David Jan Drexler
- Gene Center, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, D-81377 München, Germany.,Department of Biochemistry, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, D-81377 München, Germany
| | - Jasmin Kleinschwärzer
- Gene Center, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, D-81377 München, Germany.,Department of Biochemistry, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, D-81377 München, Germany
| | - Karl-Peter Hopfner
- Gene Center, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, D-81377 München, Germany.,Department of Biochemistry, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, D-81377 München, Germany
| | - Gregor Witte
- Gene Center, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, D-81377 München, Germany.,Department of Biochemistry, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, D-81377 München, Germany
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22
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Almeida BC, Kaczmarek JA, Figueiredo PR, Prather KLJ, Carvalho ATP. Transcription factor allosteric regulation through substrate coordination to zinc. NAR Genom Bioinform 2021; 3:lqab033. [PMID: 33987533 PMCID: PMC8092373 DOI: 10.1093/nargab/lqab033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 03/30/2021] [Accepted: 04/08/2021] [Indexed: 11/14/2022] Open
Abstract
The development of new synthetic biology circuits for biotechnology and medicine requires deeper mechanistic insight into allosteric transcription factors (aTFs). Here we studied the aTF UxuR, a homodimer of two domains connected by a highly flexible linker region. To explore how ligand binding to UxuR affects protein dynamics we performed molecular dynamics simulations in the free protein, the aTF bound to the inducer D-fructuronate or the structural isomer D-glucuronate. We then validated our results by constructing a sensor plasmid for D-fructuronate in Escherichia coli and performed site-directed mutagenesis. Our results show that zinc coordination is necessary for UxuR function since mutation to alanines prevents expression de-repression by D-fructuronate. Analyzing the different complexes, we found that the disordered linker regions allow the N-terminal domains to display fast and large movements. When the inducer is bound, UxuR can sample an open conformation with a more pronounced negative charge at the surface of the N-terminal DNA binding domains. In opposition, in the free and D-glucuronate bond forms the protein samples closed conformations, with a more positive character at the surface of the DNA binding regions. These molecular insights provide a new basis to harness these systems for biological systems engineering.
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Affiliation(s)
- Beatriz C Almeida
- CNC-Center for Neuroscience and Cell Biology, Institute for Interdisciplinary Research (IIIUC), University of Coimbra, 3004-504 Coimbra, Portugal
| | - Jennifer A Kaczmarek
- MIT-Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Pedro R Figueiredo
- CNC-Center for Neuroscience and Cell Biology, Institute for Interdisciplinary Research (IIIUC), University of Coimbra, 3004-504 Coimbra, Portugal
| | - Kristala L J Prather
- MIT-Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Alexandra T P Carvalho
- CNC-Center for Neuroscience and Cell Biology, Institute for Interdisciplinary Research (IIIUC), University of Coimbra, 3004-504 Coimbra, Portugal
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23
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Roop RM, Barton IS, Hopersberger D, Martin DW. Uncovering the Hidden Credentials of Brucella Virulence. Microbiol Mol Biol Rev 2021; 85:e00021-19. [PMID: 33568459 PMCID: PMC8549849 DOI: 10.1128/mmbr.00021-19] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Bacteria in the genus Brucella are important human and veterinary pathogens. The abortion and infertility they cause in food animals produce economic hardships in areas where the disease has not been controlled, and human brucellosis is one of the world's most common zoonoses. Brucella strains have also been isolated from wildlife, but we know much less about the pathobiology and epidemiology of these infections than we do about brucellosis in domestic animals. The brucellae maintain predominantly an intracellular lifestyle in their mammalian hosts, and their ability to subvert the host immune response and survive and replicate in macrophages and placental trophoblasts underlies their success as pathogens. We are just beginning to understand how these bacteria evolved from a progenitor alphaproteobacterium with an environmental niche and diverged to become highly host-adapted and host-specific pathogens. Two important virulence determinants played critical roles in this evolution: (i) a type IV secretion system that secretes effector molecules into the host cell cytoplasm that direct the intracellular trafficking of the brucellae and modulate host immune responses and (ii) a lipopolysaccharide moiety which poorly stimulates host inflammatory responses. This review highlights what we presently know about how these and other virulence determinants contribute to Brucella pathogenesis. Gaining a better understanding of how the brucellae produce disease will provide us with information that can be used to design better strategies for preventing brucellosis in animals and for preventing and treating this disease in humans.
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Affiliation(s)
- R Martin Roop
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA
| | - Ian S Barton
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA
| | - Dariel Hopersberger
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA
| | - Daniel W Martin
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA
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24
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Vigouroux A, Meyer T, Naretto A, Legrand P, Aumont-Nicaise M, Di Cicco A, Renoud S, Doré J, Lévy D, Vial L, Lavire C, Moréra S. Characterization of the first tetrameric transcription factor of the GntR superfamily with allosteric regulation from the bacterial pathogen Agrobacterium fabrum. Nucleic Acids Res 2021; 49:529-546. [PMID: 33313837 PMCID: PMC7797058 DOI: 10.1093/nar/gkaa1181] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Revised: 11/12/2020] [Accepted: 11/24/2020] [Indexed: 12/12/2022] Open
Abstract
A species-specific region, denoted SpG8-1b allowing hydroxycinnamic acids (HCAs) degradation is important for the transition between the two lifestyles (rhizospheric versus pathogenic) of the plant pathogen Agrobacterium fabrum. Indeed, HCAs can be either used as trophic resources and/or as induced-virulence molecules. The SpG8-1b region is regulated by two transcriptional regulators, namely, HcaR (Atu1422) and Atu1419. In contrast to HcaR, Atu1419 remains so far uncharacterized. The high-resolution crystal structures of two fortuitous citrate complexes, two DNA complexes and the apoform revealed that the tetrameric Atu1419 transcriptional regulator belongs to the VanR group of Pfam PF07729 subfamily of the large GntR superfamily. Until now, GntR regulators were described as dimers. Here, we showed that Atu1419 represses three genes of the HCAs catabolic pathway. We characterized both the effector and DNA binding sites and identified key nucleotides in the target palindrome. From promoter activity measurement using defective gene mutants, structural analysis and gel-shift assays, we propose N5,N10-methylenetetrahydrofolate as the effector molecule, which is not a direct product/substrate of the HCA degradation pathway. The Zn2+ ion present in the effector domain has both a structural and regulatory role. Overall, our work shed light on the allosteric mechanism of transcription employed by this GntR repressor.
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Affiliation(s)
- Armelle Vigouroux
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France
| | - Thibault Meyer
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, INRAE, VetAgro Sup, UMR Ecologie Microbienne, F-69622 Villeurbanne, France
| | - Anaïs Naretto
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France
| | - Pierre Legrand
- Synchrotron SOLEIL, L’Orme des Merisiers, Saint-Aubin, 91192 Gif-sur-Yvette, France
| | - Magali Aumont-Nicaise
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France
| | - Aurélie Di Cicco
- Sorbonne Université, Laboratoire Physico Chimie Curie, Institut Curie, PSL Research University, CNRS UMR168, 26 rue d’Ulm, 75005 Paris, France
| | - Sébastien Renoud
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, INRAE, VetAgro Sup, UMR Ecologie Microbienne, F-69622 Villeurbanne, France
| | - Jeanne Doré
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, INRAE, VetAgro Sup, UMR Ecologie Microbienne, F-69622 Villeurbanne, France
| | - Daniel Lévy
- Sorbonne Université, Laboratoire Physico Chimie Curie, Institut Curie, PSL Research University, CNRS UMR168, 26 rue d’Ulm, 75005 Paris, France
| | - Ludovic Vial
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, INRAE, VetAgro Sup, UMR Ecologie Microbienne, F-69622 Villeurbanne, France
| | - Céline Lavire
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, INRAE, VetAgro Sup, UMR Ecologie Microbienne, F-69622 Villeurbanne, France
| | - Solange Moréra
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France
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25
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Arya G, Pal M, Sharma M, Singh B, Singh S, Agrawal V, Chaba R. Molecular insights into effector binding by DgoR, a GntR/FadR family transcriptional repressor of D-galactonate metabolism in Escherichia coli. Mol Microbiol 2020; 115:591-609. [PMID: 33068046 DOI: 10.1111/mmi.14625] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Revised: 10/06/2020] [Accepted: 10/09/2020] [Indexed: 01/23/2023]
Abstract
Several GntR/FadR transcriptional regulators govern sugar acid metabolism in bacteria. Although effectors have been identified for a few sugar acid regulators, the mode of effector binding is unknown. Even in the overall FadR subfamily, there are limited details on effector-regulator interactions. Here, we identified the effector-binding cavity in Escherichia coli DgoR, a FadR subfamily transcriptional repressor of D-galactonate metabolism that employs D-galactonate as its effector. Using a genetic screen, we isolated several dgoR superrepressor alleles. Blind docking suggested eight amino acids corresponding to these alleles to form a part of the effector-binding cavity. In vivo and in vitro assays showed that these mutations compromise the inducibility of DgoR without affecting its oligomeric status or affinity for target DNA. Taking Bacillus subtilis GntR as a representative, we demonstrated that the effector-binding cavity is similar among FadR subfamily sugar acid regulators. Finally, a comparison of sugar acid regulators with other FadR members suggested conserved features of effector-regulator recognition within the FadR subfamily. Sugar acid metabolism is widely implicated in bacterial colonization and virulence. The present study sets the basis to investigate the influence of natural genetic variations in FadR subfamily regulators on their sensitivity to sugar acids and ultimately on host-bacterial interactions.
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Affiliation(s)
- Garima Arya
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, SAS Nagar, Punjab, India
| | - Mohinder Pal
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, SAS Nagar, Punjab, India
| | - Monika Sharma
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, SAS Nagar, India
| | - Bhupinder Singh
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, SAS Nagar, Punjab, India
| | - Swati Singh
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, SAS Nagar, Punjab, India
| | - Vishal Agrawal
- Department of Biochemistry, Panjab University, Chandigarh, India
| | - Rachna Chaba
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, SAS Nagar, Punjab, India
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26
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Graf von Armansperg B, Koller F, Gericke N, Hellwig M, Jagtap PKA, Heermann R, Hennig J, Henle T, Lassak J. Transcriptional regulation of the N ε -fructoselysine metabolism in Escherichia coli by global and substrate-specific cues. Mol Microbiol 2020; 115:175-190. [PMID: 32979851 DOI: 10.1111/mmi.14608] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 09/08/2020] [Accepted: 09/11/2020] [Indexed: 12/19/2022]
Abstract
Thermally processed food is an important part of the human diet. Heat-treatment, however, promotes the formation of so-called Amadori rearrangement products, such as fructoselysine. The gut microbiota including Escherichia coli can utilize these compounds as a nutrient source. While the degradation route for fructoselysine is well described, regulation of the corresponding pathway genes frlABCD remained poorly understood. Here, we used bioinformatics combined with molecular and biochemical analyses and show that fructoselysine metabolism in E. coli is tightly controlled at the transcriptional level. The global regulator CRP (CAP) as well as the alternative sigma factor σ32 (RpoH) contribute to promoter activation at high cAMP-levels and inside warm-blooded hosts, respectively. In addition, we identified and characterized a transcriptional regulator FrlR, encoded adjacent to frlABCD, as fructoselysine-6-phosphate specific repressor. Our study provides profound evidence that the interplay of global and substrate-specific regulation is a perfect adaptation strategy to efficiently utilize unusual substrates within the human gut environment.
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Affiliation(s)
| | - Franziska Koller
- Department of Biology I, Microbiology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Nicola Gericke
- Department of Biology I, Microbiology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Michael Hellwig
- Chair of Food Chemistry, Technische Universität Dresden, Dresden, Germany
| | | | - Ralf Heermann
- Institute of Molecular Physiology, Microbiology and Wine Research, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Janosch Hennig
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Thomas Henle
- Chair of Food Chemistry, Technische Universität Dresden, Dresden, Germany
| | - Jürgen Lassak
- Department of Biology I, Microbiology, Ludwig-Maximilians-Universität München, Munich, Germany
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27
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Dudek M, Dieudonné A, Jouanneau D, Rochat T, Michel G, Sarels B, Thomas F. Regulation of alginate catabolism involves a GntR family repressor in the marine flavobacterium Zobellia galactanivorans DsijT. Nucleic Acids Res 2020; 48:7786-7800. [PMID: 32585009 PMCID: PMC7641319 DOI: 10.1093/nar/gkaa533] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 06/02/2020] [Accepted: 06/10/2020] [Indexed: 12/19/2022] Open
Abstract
Marine flavobacteria possess dedicated Polysaccharide Utilization Loci (PULs) enabling efficient degradation of a variety of algal polysaccharides. The expression of these PULs is tightly controlled by the presence of the substrate, yet details on the regulatory mechanisms are still lacking. The marine flavobacterium Zobellia galactanivorans DsijT digests many algal polysaccharides, including alginate from brown algae. Its complex Alginate Utilization System (AUS) comprises a PUL and several other loci. Here, we showed that the expression of the AUS is strongly and rapidly (<30 min) induced upon addition of alginate, leading to biphasic substrate utilization. Polymeric alginate is first degraded into smaller oligosaccharides that accumulate in the extracellular medium before being assimilated. We found that AusR, a GntR family protein encoded within the PUL, regulates alginate catabolism by repressing the transcription of most AUS genes. Based on our genetic, genomic, transcriptomic and biochemical results, we propose the first model of regulation for a PUL in marine bacteria. AusR binds to promoters of AUS genes via single, double or triple copies of operator. Upon addition of alginate, secreted enzymes expressed at a basal level catalyze the initial breakdown of the polymer. Metabolic intermediates produced during degradation act as effectors of AusR and inhibit the formation of AusR/DNA complexes, thus lifting transcriptional repression.
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Affiliation(s)
- Magda Dudek
- Sorbonne Université, CNRS, Integrative Biology of Marine Models (LBI2M), Station Biologique de Roscoff (SBR), 29680 Roscoff, France
| | - Anissa Dieudonné
- Sorbonne Université, CNRS, Integrative Biology of Marine Models (LBI2M), Station Biologique de Roscoff (SBR), 29680 Roscoff, France
| | - Diane Jouanneau
- Sorbonne Université, CNRS, Integrative Biology of Marine Models (LBI2M), Station Biologique de Roscoff (SBR), 29680 Roscoff, France
| | - Tatiana Rochat
- Université Paris-Saclay, INRAE, UVSQ, VIM, 78350, Jouy-en-Josas, France
| | - Gurvan Michel
- Sorbonne Université, CNRS, Integrative Biology of Marine Models (LBI2M), Station Biologique de Roscoff (SBR), 29680 Roscoff, France
| | - Benoit Sarels
- Sorbonne Université, CNRS, Laboratoire Jacques-Louis Lions, Université de Paris, 75252 Paris, France
| | - François Thomas
- Sorbonne Université, CNRS, Integrative Biology of Marine Models (LBI2M), Station Biologique de Roscoff (SBR), 29680 Roscoff, France
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28
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Wang T, Qi Y, Wang Z, Zhao J, Ji L, Li J, Cai Z, Yang L, Wu M, Liang H. Coordinated regulation of anthranilate metabolism and bacterial virulence by the GntR family regulator MpaR inPseudomonas aeruginosa. Mol Microbiol 2020; 114:857-869. [PMID: 32748556 DOI: 10.1111/mmi.14584] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Revised: 07/23/2020] [Accepted: 07/27/2020] [Indexed: 12/22/2022]
Affiliation(s)
- Tietao Wang
- Key Laboratory of Resources Biology and Biotechnology in Western China Ministry of Education College of Life Sciences Northwest University Xi'an China
| | - Yihang Qi
- Key Laboratory of Resources Biology and Biotechnology in Western China Ministry of Education College of Life Sciences Northwest University Xi'an China
| | - Zhihan Wang
- West China School of Basic Medical Science & Forensic Medicine Sichuan University ChengDu China
| | - Jingru Zhao
- Key Laboratory of Resources Biology and Biotechnology in Western China Ministry of Education College of Life Sciences Northwest University Xi'an China
| | - Linxuan Ji
- Key Laboratory of Resources Biology and Biotechnology in Western China Ministry of Education College of Life Sciences Northwest University Xi'an China
| | - Jun Li
- College of Bioengineering and Biotechnology Zhejiang University of Technology Hangzhou China
| | - Zhao Cai
- School of Medicine Southern University of Science and Technology ShenZhen China
| | - Liang Yang
- School of Medicine Southern University of Science and Technology ShenZhen China
| | - Min Wu
- Department of Basic Science School of Medicine and Health Science University of North Dakota Grand Forks ND USA
| | - Haihua Liang
- Key Laboratory of Resources Biology and Biotechnology in Western China Ministry of Education College of Life Sciences Northwest University Xi'an China
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29
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Labella JI, Cantos R, Salinas P, Espinosa J, Contreras A. Distinctive Features of PipX, a Unique Signaling Protein of Cyanobacteria. Life (Basel) 2020; 10:life10060079. [PMID: 32481703 PMCID: PMC7344720 DOI: 10.3390/life10060079] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Revised: 05/23/2020] [Accepted: 05/26/2020] [Indexed: 12/20/2022] Open
Abstract
PipX is a unique cyanobacterial protein identified by its ability to bind to PII and NtcA, two key regulators involved in the integration of signals of the nitrogen/carbon and energy status, with a tremendous impact on nitrogen assimilation and gene expression in cyanobacteria. PipX provides a mechanistic link between PII, the most widely distributed signaling protein, and NtcA, a global transcriptional regulator of cyanobacteria. PII, required for cell survival unless PipX is inactivated or down-regulated, functions by protein–protein interactions with transcriptional regulators, transporters, and enzymes. In addition, PipX appears to be involved in a wider signaling network, supported by the following observations: (i) PII–PipX complexes interact with PlmA, an as yet poorly characterized transcriptional regulator also restricted to cyanobacteria; (ii) the pipX gene is functionally connected with pipY, a gene encoding a universally conserved pyridoxal phosphate binding protein (PLPBP) involved in vitamin B6 and amino acid homeostasis, whose loss-of-function mutations cause B6-dependent epilepsy in humans, and (iii) pipX is part of a relatively robust, six-node synteny network that includes pipY and four additional genes that might also be functionally connected with pipX. In this overview, we propose that the study of the protein–protein interaction and synteny networks involving PipX would contribute to understanding the peculiarities and idiosyncrasy of signaling pathways that are conserved in cyanobacteria.
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30
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Frezzini M, Narzi D, Sciolari AM, Guidoni L, Pascarella S. Molecular dynamics of an asymmetric form of GabR, a bacterial transcriptional regulator. Biophys Chem 2020; 262:106380. [PMID: 32413777 DOI: 10.1016/j.bpc.2020.106380] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 04/14/2020] [Accepted: 04/15/2020] [Indexed: 01/20/2023]
Abstract
GabR is a bacterial transcription regulator with a dimeric structure in which each subunit includes a wHTH (winged Helix-Turn-Helix) domain connected through a peptide linker to a large C-terminal domain folded as the enzyme aspartate aminotransferase (AAT). In Bacillus subtilis, GabR activates the genes involved in the metabolism of γ-amino butyric acid (GABA) upon formation of a PLP-GABA adduct. Recently, the crystallographic structure of an asymmetric form of GabR has been solved. This form (semi-holo) has one active site binding PLP as internal aldimine and the other the PLP-GABA complex. This work reports a molecular dynamics (MD) study aimed at understanding the characteristics of the asymmetric GabR form and compare them to the dynamics properties of previously studied symmetric holo (internal PLP aldimine at both active sites) and holo-GABA (containing PLP-GABA adducts) GabRs. Standard molecular dynamics and data analysis techniques have been used. The results indicate a remarkable asymmetry in the mobility and interactions of the different structural portions of the semi-holo GabR and of a few residues at the active site. The pattern is different from that observed in the other symmetrical GabR forms. The asymmetric perturbation of the active site residues may suggest the existence of a form of allosteric interference between the two active sites.
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Affiliation(s)
- Mario Frezzini
- Department of Information Engineering, Computer Science and Mathematics, University of L'Aquila, 67100 L'Aquila, Italy.
| | - Daniele Narzi
- Department of Physics and Chemistry Sciences, University of L'Aquila, 67100 L'Aquila, Italy.
| | | | - Leonardo Guidoni
- Department of Physics and Chemistry Sciences, University of L'Aquila, 67100 L'Aquila, Italy.
| | - Stefano Pascarella
- Department of Biochemical Sciences "A. Rossi Fanelli", Sapienza University of Rome, 00185 Rome, Italy.
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31
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Phale PS, Malhotra H, Shah BA. Degradation strategies and associated regulatory mechanisms/features for aromatic compound metabolism in bacteria. ADVANCES IN APPLIED MICROBIOLOGY 2020; 112:1-65. [PMID: 32762865 DOI: 10.1016/bs.aambs.2020.02.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
As a result of anthropogenic activity, large number of recalcitrant aromatic compounds have been released into the environment. Consequently, microbial communities have adapted and evolved to utilize these compounds as sole carbon source, under both aerobic and anaerobic conditions. The constitutive expression of enzymes necessary for metabolism imposes a heavy energy load on the microbe which is overcome by arrangement of degradative genes as operons which are induced by specific inducers. The segmentation of pathways into upper, middle and/or lower operons has allowed microbes to funnel multiple compounds into common key aromatic intermediates which are further metabolized through central carbon pathway. Various proteins belonging to diverse families have evolved to regulate the transcription of individual operons participating in aromatic catabolism. These proteins, complemented with global regulatory mechanisms, carry out the regulation of aromatic compound metabolic pathways in a concerted manner. Additionally, characteristics like chemotaxis, preferential utilization, pathway compartmentalization and biosurfactant production confer an advantage to the microbe, thus making bioremediation of the aromatic pollutants more efficient and effective.
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Affiliation(s)
- Prashant S Phale
- Department of Biosciences and Bioengineering, Indian Institute of Technology-Bombay, Mumbai, India.
| | - Harshit Malhotra
- Department of Biosciences and Bioengineering, Indian Institute of Technology-Bombay, Mumbai, India
| | - Bhavik A Shah
- Department of Biosciences and Bioengineering, Indian Institute of Technology-Bombay, Mumbai, India
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32
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Frezzini M, Guidoni L, Pascarella S. Conformational transitions induced by γ-amino butyrate binding in GabR, a bacterial transcriptional regulator. Sci Rep 2019; 9:19319. [PMID: 31848410 PMCID: PMC6917764 DOI: 10.1038/s41598-019-55581-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2019] [Accepted: 11/20/2019] [Indexed: 11/09/2022] Open
Abstract
GabR from Bacillus subtilis is a transcriptional regulator of the MocR subfamily of GntR regulators. The MocR architecture is characterized by the presence of an N-terminal winged-Helix-Turn-Helix domain and a C-terminal domain folded as the pyridoxal 5′-phosphate (PLP) dependent aspartate aminotransferase (AAT). The two domains are linked by a peptide bridge. GabR activates transcription of genes involved in γ-amino butyrate (GABA) degradation upon binding of PLP and GABA. This work is aimed at contributing to the understanding of the molecular mechanism underlying the GabR transcription activation upon GABA binding. To this purpose, the structure of the entire GabR dimer with GABA external aldimine (holo-GABA) has been reconstructed using available crystallographic data. The structure of the apo (without any ligand) and holo (with PLP) GabR forms have been derived from the holo-GABA. An extensive 1 μs comparative molecular dynamics (MD) has been applied to the three forms. Results showed that the presence of GABA external aldimine stiffens the GabR, stabilizes the AAT domain in the closed form and couples the AAT and HTH domains dynamics. Apo and holo GabR appear more flexible especially at the level of the HTH and linker portions and small AAT subdomain.
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Affiliation(s)
- Mario Frezzini
- Department of Information Engineering, Computer Science and Mathematics, University of L'Aquila, 67100, L'Aquila, Italy
| | - Leonardo Guidoni
- Department of Physics and Chemistry Sciences, University of L'Aquila, 67100, L'Aquila, Italy
| | - Stefano Pascarella
- Department of Biochemical Sciences "A Rossi Fanelli", Sapienza, University of Rome, 00185, Rome, Italy.
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Lemmens L, Tilleman L, De Koning E, Valegård K, Lindås AC, Van Nieuwerburgh F, Maes D, Peeters E. YtrA Sa, a GntR-Family Transcription Factor, Represses Two Genetic Loci Encoding Membrane Proteins in Sulfolobus acidocaldarius. Front Microbiol 2019; 10:2084. [PMID: 31552000 PMCID: PMC6746942 DOI: 10.3389/fmicb.2019.02084] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 08/23/2019] [Indexed: 11/25/2022] Open
Abstract
In bacteria, the GntR family is a widespread family of transcription factors responsible for the regulation of a myriad of biological processes. In contrast, despite their occurrence in archaea only a little information is available on the function of GntR-like transcription factors in this domain of life. The thermoacidophilic crenarchaeon Sulfolobus acidocaldarius harbors a GntR-like regulator belonging to the YtrA subfamily, encoded as the first gene in an operon with a second gene encoding a putative membrane protein. Here, we present a detailed characterization of this regulator, named YtrASa, with a focus on regulon determination and mechanistic analysis with regards to DNA binding. Genome-wide chromatin immunoprecipitation and transcriptome experiments, the latter employing a ytrASa overexpression strain, demonstrate that the regulator acts as a repressor on a very restricted regulon, consisting of only two targets including the operon encoding its own gene and a distinct genetic locus encoding another putative membrane protein. For both targets, a conserved 14-bp semi-palindromic binding motif was delineated that covers the transcriptional start site and that is surrounded by additional half-site motifs. The crystallographic structure of YtrASa was determined, revealing a compact dimeric structure in which the DNA-binding motifs are oriented ideally to enable a specific high-affinity interaction with the core binding motif. This study provides new insights into the functioning of a YtrA-like regulator in the archaeal domain of life.
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Affiliation(s)
- Liesbeth Lemmens
- Research Group of Microbiology, Department of Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Laurentijn Tilleman
- Laboratory for Pharmaceutical Biotechnology, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium
| | - Ezra De Koning
- Research Group of Microbiology, Department of Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Karin Valegård
- Molecular Biophysics, Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Ann-Christin Lindås
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Filip Van Nieuwerburgh
- Laboratory for Pharmaceutical Biotechnology, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium
| | - Dominique Maes
- Structural Biology Brussels, Department of Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Eveline Peeters
- Research Group of Microbiology, Department of Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium
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Kotowska M, Świat M, Zarȩba-Pasławska J, Jaworski P, Pawlik K. A GntR-Like Transcription Factor HypR Regulates Expression of Genes Associated With L-Hydroxyproline Utilization in Streptomyces coelicolor A3(2). Front Microbiol 2019; 10:1451. [PMID: 31297104 PMCID: PMC6608401 DOI: 10.3389/fmicb.2019.01451] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 06/11/2019] [Indexed: 11/13/2022] Open
Abstract
Bacteria from the genus Streptomyces have been long exploited as the most prolific producers of antibiotics, other secondary metabolites and enzymes. They are important members of soil microbial communities that can adapt to changing conditions thank to the fine regulation of gene expression in response to environmental signals. Streptomyces coelicolor A3(2) is a model organism for molecular studies with the most deeply recognized interactions within the complex metabolic and regulatory network. However, details about molecular signals recognized by specialized regulatory proteins as well as their direct targets are often missing. We describe here a zinc-binding protein HypR (SCO6294) which belongs to FadR subfamily of GntR-like regulators. The DNA sequence 5'-TACAATGTCAC-3' recognized by the HypR protein in its own promoter region was identified by DNase I footprinting. Binding of six DNA fragments containing similar sequences located in other promoter regions were confirmed by the electrophoretic mobility shift assay (EMSA). The sequences of 7 in vitro-determined binding sites were assembled to generate a logo of the HypR binding motif, 5'-CTNTGC(A/C)ATGTCAC-3'. Comparison of luciferase reporter genes expression under the control of cloned promoter regions in S. coelicolor A3(2) wild type and deletion mutant strains revealed, that the HypR protein acts as a repressor of its target genes. Genes belonging to the regulon of HypR code for enzymes putatively involved in collagen degradation and utilization of L-hydroxyproline (L-Hyp) as concluded from predicted structure and conserved domains. Their transcription is induced in the wild type strain by the addition of L-Hyp to the culture medium. Moreover, knockout of one of the genes from the predicted L-Hyp utilization operon abolished the ability of the strain to grow on L-Hyp as a sole source of carbon. To our knowledge, this work is the first indication of the existence of the pathway of L-hydroxyproline catabolism in Streptomycetes.
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Affiliation(s)
- Magdalena Kotowska
- Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Wrocław, Poland
| | | | | | | | - Krzysztof Pawlik
- Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Wrocław, Poland
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35
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Ali F, Ahmed S, Swati ZNK, Akbar S. DP-BINDER: machine learning model for prediction of DNA-binding proteins by fusing evolutionary and physicochemical information. J Comput Aided Mol Des 2019; 33:645-658. [PMID: 31123959 DOI: 10.1007/s10822-019-00207-x] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 05/18/2019] [Indexed: 12/28/2022]
Abstract
DNA-binding proteins (DBPs) participate in various biological processes including DNA replication, recombination, and repair. In the human genome, about 6-7% of these proteins are utilized for genes encoding. DBPs shape the DNA into a compact structure known chromatin while some of these proteins regulate the chromosome packaging and transcription process. In the pharmaceutical industry, DBPs are used as a key component of antibiotics, steroids, and cancer drugs. These proteins also involve in biophysical, biological, and biochemical studies of DNA. Due to the crucial role in various biological activities, identification of DBPs is a hot issue in protein science. A series of experimental and computational methods have been proposed, however, some methods didn't achieve the desired results while some are inadequate in its accuracy and authenticity. Still, it is highly desired to present more intelligent computational predictors. In this work, we introduce an innovative computational method namely DP-BINDER based on physicochemical and evolutionary information. We captured local highly decisive features from physicochemical properties of primary protein sequences via normalized Moreau-Broto autocorrelation (NMBAC) and evolutionary information by position specific scoring matrix-transition probability composition (PSSM-TPC) and pseudo-position specific scoring matrix (PsePSSM) using training and independent datasets. The optimal features were selected by the support vector machine-recursive feature elimination and correlation bias reduction (SVM-RFE + CBR) from fused features and were fed into random forest (RF) and support vector machine (SVM). Our method attained 92.46% and 89.58% accuracy with jackknife and ten-fold cross-validation, respectively on the training dataset, while 81.17% accuracy on the independent dataset for prediction of DBPs. These results demonstrate that our method attained the highest success rate in the literature. The superiority of DP-BINDER over existing approaches due to several reasons including abstraction of local dominant features via effective feature descriptors, utilization of appropriate feature selection algorithms and effective classifier.
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Affiliation(s)
- Farman Ali
- School of Computer Science and Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China.
| | - Saeed Ahmed
- School of Computer Science and Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China
| | - Zar Nawab Khan Swati
- School of Computer Science and Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China
- Department of Computer Science, Karakoram International University, Gilgit, Gilgit-Baltistan, 15100, Pakistan
| | - Shahid Akbar
- Department of Computer Science, Abdul Wali Khan University, Mardan, Pakistan
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Identification of a GntR family regulator BusR Tha and its regulatory mechanism in the glycine betaine ABC transport system of Tetragenococcus halophilus. Extremophiles 2019; 23:451-460. [PMID: 31053934 DOI: 10.1007/s00792-019-01096-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 04/25/2019] [Indexed: 10/26/2022]
Abstract
Glycine betaine is one of the most effective compatible solutes of the halophilic lactic acid bacterium Tetragenococcus halophilus, the transportation of which is essential for its survival under salinity stress condition. In the current study, we attempted to define a glycine betaine ABC transporter system of T. halophilus, busATha, which plays an important role in adapting to salinity condition. The expression of busATha enhanced the growth of the recombinant strain under high salinity. BusRTha, a transcription regulator that represses the expression of busATha, was characterized, and the repression was abrogated under high salinity. The binding of the regulator was demonstrated through electrophoretic mobility shift assays, and the binding sites were characterized as 5'-AAA(T/G)TGAC(C/A)(G/A)T(C/A)C-3'. This is the first studied transcription regulator of T. halophilus, and our findings provide insights into the molecular mechanism of halophilic life and tools for further application of halophiles as chassis in industrial biotechnology.
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Castrejón-Godínez ML, Ortiz-Hernández ML, Salazar E, Encarnación S, Mussali-Galante P, Tovar-Sánchez E, Sánchez-Salinas E, Rodríguez A. Transcriptional analysis reveals the metabolic state of Burkholderia zhejiangensis CEIB S4-3 during methyl parathion degradation. PeerJ 2019; 7:e6822. [PMID: 31086743 PMCID: PMC6486813 DOI: 10.7717/peerj.6822] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Accepted: 03/20/2019] [Indexed: 12/17/2022] Open
Abstract
Burkholderia zhejiangensis CEIB S4-3 has the ability to degrade methyl parathion (MP) and its main hydrolysis byproduct p-nitrophenol (PNP). According to genomic data, several genes related with metabolism of MP and PNP were identified in this strain. However, the metabolic state of the strain during the MP degradation has not been evaluated. In the present study, we analyzed gene expression changes during MP hydrolysis and PNP degradation through a transcriptomic approach. The transcriptional analysis revealed differential changes in the expression of genes involved in important cellular processes, such as energy production and conversion, transcription, amino acid transport and metabolism, translation, ribosomal structure and biogenesis, among others. Transcriptomic data also exhibited the overexpression of both PNP-catabolic gene clusters (pnpABA′E1E2FDC and pnpE1E2FDC) present in the strain. We found and validated by quantitative reverse transcription polymerase chain reaction the expression of the methyl parathion degrading gene, as well as the genes responsible for PNP degradation contained in two clusters. This proves the MP degradation pathway by the strain tested in this work. The exposure to PNP activates, in the first instance, the expression of the transcriptional regulators multiple antibiotic resistance regulator and Isocitrate Lyase Regulator (IclR), which are important in the regulation of genes from aromatic compound catabolism, as well as the expression of genes that encode transporters, permeases, efflux pumps, and porins related to the resistance to multidrugs and other xenobiotics. In the presence of the pesticide, 997 differentially expressed genes grouped in 104 metabolic pathways were observed. This report is the first to describe the transcriptomic analysis of a strain of B. zhejiangensis during the biodegradation of PNP.
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Affiliation(s)
| | - Ma Laura Ortiz-Hernández
- Centro de Investigación en Biotecnología, Universidad Autónoma del Estado de Morelos, Cuernavaca, Morelos, Mexico
| | - Emmanuel Salazar
- Centro de Investigación en Biotecnología, Universidad Autónoma del Estado de Morelos, Cuernavaca, Morelos, Mexico
| | - Sergio Encarnación
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, Mexico
| | - Patricia Mussali-Galante
- Centro de Investigación en Biotecnología, Universidad Autónoma del Estado de Morelos, Cuernavaca, Morelos, Mexico
| | - Efraín Tovar-Sánchez
- Centro de Investigación en Biodiversidad y Conservación, Universidad Autónoma del Estado de Morelos, Cuernavaca, Morelos, Mexico
| | - Enrique Sánchez-Salinas
- Centro de Investigación en Biotecnología, Universidad Autónoma del Estado de Morelos, Cuernavaca, Morelos, Mexico
| | - Alexis Rodríguez
- Centro de Investigación en Biotecnología, Universidad Autónoma del Estado de Morelos, Cuernavaca, Morelos, Mexico
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38
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Pascarella S. Computational classification of MocR transcriptional regulators into subgroups as a support for experimental and functional characterization. Bioinformation 2019; 15:151-159. [PMID: 31435161 PMCID: PMC6677901 DOI: 10.6026/97320630015151] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 02/03/2019] [Indexed: 11/23/2022] Open
Abstract
MocR bacterial transcriptional regulators are a subfamily within the GntR family. The MocR proteins possess an N-terminal domain containing the winged Helix-Turn-Helix (wHTH) motif and a C-terminal domain whose architecture is homologous to the fold type-I pyridoxal 5'-phosphate (PLP) dependent enzymes and whose archetypical protein is aspartate aminotransferase (AAT). The ancestor of the fold type-I PLP dependent super-family is considered one of the earliest enzymes. The members of this super-family are the product of evolution which resulted in a diversified protein population able to catalyze a set of reactions on substrates often containing amino groups. The MocR regulators are activators or repressors of gene control within many metabolic pathways often involving PLP enzymes. This diversity implies that MocR specifically responds to different classes of effector molecules. Therefore, it is of interest to compare the AAT domains of MocR from six bacteria phyla. Multi dimensional scaling and cluster analyses suggested that at least three subgroups exist within the population that reflects functional specialization rather than taxonomic origin. The AAT-domains of the three clusters display variable degree of similarity to different fold type-I PLP enzyme families. The results support the hypothesis that independent fusion events generated at least three different MocR subgroups.
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Affiliation(s)
- Stefano Pascarella
- Structural bioinformatics and Molecular modelling Lab;Dipartimento di Scienze biochimiche;Sapienza Universita di Roma;00185 Roma,Italy
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39
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Molecular and Functional Insights into the Regulation of d-Galactonate Metabolism by the Transcriptional Regulator DgoR in Escherichia coli. J Bacteriol 2019; 201:JB.00281-18. [PMID: 30455279 DOI: 10.1128/jb.00281-18] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2018] [Accepted: 11/07/2018] [Indexed: 12/11/2022] Open
Abstract
d-Galactonate, an aldonic sugar acid, is used as a carbon source by Escherichia coli, and the structural dgo genes involved in its metabolism have previously been investigated. Here, using genetic, biochemical and bioinformatics approaches, we present the first detailed molecular and functional insights into the regulation of d-galactonate metabolism in E. coli K-12 by the transcriptional regulator DgoR. We found that dgoR deletion accelerates the growth of E. coli in d-galactonate concomitant with the strong constitutive expression of dgo genes. In the dgo locus, sequence upstream of dgoR alone harbors the d-galactonate-inducible promoter that likely drives the expression of all dgo genes. DgoR exerts repression on the dgo operon by binding two inverted repeats overlapping the dgo promoter. Binding of d-galactonate induces a conformational change in DgoR to derepress the dgo operon. The findings from our work firmly place DgoR in the GntR family of transcriptional regulators: DgoR binds an operator sequence [5'-TTGTA(G/C)TACA(A/T)-3'] matching the signature of GntR family members that recognize inverted repeats [5'-(N) y GT(N) x AC(N) y -3', where x and y indicate the number of nucleotides, which varies], and it shares critical protein-DNA contacts. We also identified features in DgoR that are otherwise less conserved in the GntR family. Recently, missense mutations in dgoR were recovered in a natural E. coli isolate adapted to the mammalian gut. Our results show these mutants to be DNA binding defective, emphasizing that mutations in the dgo-regulatory elements are selected in the host to allow simultaneous induction of dgo genes. The present study sets the basis to explore the regulation of dgo genes in additional enterobacterial strains where they have been implicated in host-bacterium interactions.IMPORTANCE d-Galactonate is a widely prevalent aldonic sugar acid. Despite the proposed significance of the d-galactonate metabolic pathway in the interaction of enteric bacteria with their hosts, there are no details on its regulation even in Escherichia coli, which has been known to utilize d-galactonate since the 1970s. Here, using multiple methodologies, we identified the promoter, operator, and effector of DgoR, the transcriptional repressor of d-galactonate metabolism in E. coli We establish DgoR as a GntR family transcriptional regulator. Recently, a human urinary tract isolate of E. coli introduced in the mouse gut was found to accumulate missense mutations in dgoR Our results show these mutants to be DNA binding defective, hence emphasizing the role of the d-galactonate metabolic pathway in bacterial colonization of the mammalian gut.
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40
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Forcada-Nadal A, Llácer JL, Contreras A, Marco-Marín C, Rubio V. The P II-NAGK-PipX-NtcA Regulatory Axis of Cyanobacteria: A Tale of Changing Partners, Allosteric Effectors and Non-covalent Interactions. Front Mol Biosci 2018; 5:91. [PMID: 30483512 PMCID: PMC6243067 DOI: 10.3389/fmolb.2018.00091] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2018] [Accepted: 10/18/2018] [Indexed: 11/13/2022] Open
Abstract
PII, a homotrimeric very ancient and highly widespread (bacteria, archaea, plants) key sensor-transducer protein, conveys signals of abundance or poorness of carbon, energy and usable nitrogen, converting these signals into changes in the activities of channels, enzymes, or of gene expression. PII sensing is mediated by the PII allosteric effectors ATP, ADP (and, in some organisms, AMP), 2-oxoglutarate (2OG; it reflects carbon abundance and nitrogen scarcity) and, in many plants, L-glutamine. Cyanobacteria have been crucial for clarification of the structural bases of PII function and regulation. They are the subject of this review because the information gathered on them provides an overall structure-based view of a PII regulatory network. Studies on these organisms yielded a first structure of a PII complex with an enzyme, (N-acetyl-Lglutamate kinase, NAGK), deciphering how PII can cause enzyme activation, and how it promotes nitrogen stockpiling as arginine in cyanobacteria and plants. They have also revealed the first clear-cut mechanism by which PII can control gene expression. A small adaptor protein, PipX, is sequestered by PII when nitrogen is abundant and is released when is scarce, swapping partner by binding to the 2OG-activated transcriptional regulator NtcA, co-activating it. The structures of PII-NAGK, PII-PipX, PipX alone, of NtcA in inactive and 2OG-activated forms and as NtcA-2OG-PipX complex, explain structurally PII regulatory functions and reveal the changing shapes and interactions of the T-loops of PII depending on the partner and on the allosteric effectors bound to PII. Cyanobacterial studies have also revealed that in the PII-PipX complex PipX binds an additional transcriptional factor, PlmA, thus possibly expanding PipX roles beyond NtcA-dependency. Further exploration of these roles has revealed a functional interaction of PipX with PipY, a pyridoxal-phosphate (PLP) protein involved in PLP homeostasis whose mutations in the human ortholog cause epilepsy. Knowledge of cellular levels of the different components of this PII-PipX regulatory network and of KD values for some of the complexes provides the basic background for gross modeling of the system at high and low nitrogen abundance. The cyanobacterial network can guide searches for analogous components in other organisms, particularly of PipX functional analogs.
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Affiliation(s)
- Alicia Forcada-Nadal
- Instituto de Biomedicina de Valencia del Consejo Superior de Investigaciones Científicas, Valencia, Spain.,Departamento de Fisiología, Genética y Microbiología, Universidad de Alicante, Alicante, Spain
| | - José Luis Llácer
- Instituto de Biomedicina de Valencia del Consejo Superior de Investigaciones Científicas, Valencia, Spain.,Group 739, Centro de Investigación Biomédica en Red de Enfermedades Raras - Instituto de Salud Carlos III, Valencia, Spain
| | - Asunción Contreras
- Departamento de Fisiología, Genética y Microbiología, Universidad de Alicante, Alicante, Spain
| | - Clara Marco-Marín
- Instituto de Biomedicina de Valencia del Consejo Superior de Investigaciones Científicas, Valencia, Spain.,Group 739, Centro de Investigación Biomédica en Red de Enfermedades Raras - Instituto de Salud Carlos III, Valencia, Spain
| | - Vicente Rubio
- Instituto de Biomedicina de Valencia del Consejo Superior de Investigaciones Científicas, Valencia, Spain.,Group 739, Centro de Investigación Biomédica en Red de Enfermedades Raras - Instituto de Salud Carlos III, Valencia, Spain
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Pinheiro J, Lisboa J, Pombinho R, Carvalho F, Carreaux A, Brito C, Pöntinen A, Korkeala H, dos Santos NM, Morais-Cabral JH, Sousa S, Cabanes D. MouR controls the expression of the Listeria monocytogenes Agr system and mediates virulence. Nucleic Acids Res 2018; 46:9338-9352. [PMID: 30011022 PMCID: PMC6182135 DOI: 10.1093/nar/gky624] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 06/25/2018] [Accepted: 06/28/2018] [Indexed: 12/11/2022] Open
Abstract
The foodborne pathogen Listeria monocytogenes (Lm) causes invasive infection in susceptible animals and humans. To survive and proliferate within hosts, this facultative intracellular pathogen tightly coordinates the expression of a complex regulatory network that controls the expression of virulence factors. Here, we identified and characterized MouR, a novel virulence regulator of Lm. Through RNA-seq transcriptomic analysis, we determined the MouR regulon and demonstrated how MouR positively controls the expression of the Agr quorum sensing system (agrBDCA) of Lm. The MouR three-dimensional structure revealed a dimeric DNA-binding transcription factor belonging to the VanR class of the GntR superfamily of regulatory proteins. We also showed that by directly binding to the agr promoter region, MouR ultimately modulates chitinase activity and biofilm formation. Importantly, we demonstrated by in vitro cell invasion assays and in vivo mice infections the role of MouR in Lm virulence.
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Affiliation(s)
- Jorge Pinheiro
- Group of Molecular Microbiology, IBMC – Institute for Molecular and Cell Biology; i3S – Institute for Research and Innovation in Health, Porto 4200-135, Portugal
- ICBAS- Instituto de Ciências Biomédicas Abel Salazar, University of Porto, Porto 4200-135, Portugal
| | - Johnny Lisboa
- Group of Fish Immunology & Vaccinology, IBMC – Institute for Molecular and Cell Biology; i3S – Institute for Research and Innovation in Health, Porto 4200-135, Portugal
| | - Rita Pombinho
- Group of Molecular Microbiology, IBMC – Institute for Molecular and Cell Biology; i3S – Institute for Research and Innovation in Health, Porto 4200-135, Portugal
- ICBAS- Instituto de Ciências Biomédicas Abel Salazar, University of Porto, Porto 4200-135, Portugal
| | - Filipe Carvalho
- Group of Molecular Microbiology, IBMC – Institute for Molecular and Cell Biology; i3S – Institute for Research and Innovation in Health, Porto 4200-135, Portugal
- ICBAS- Instituto de Ciências Biomédicas Abel Salazar, University of Porto, Porto 4200-135, Portugal
| | - Alexis Carreaux
- Group of Molecular Microbiology, IBMC – Institute for Molecular and Cell Biology; i3S – Institute for Research and Innovation in Health, Porto 4200-135, Portugal
- SDV - UFR Sciences Du Vivant: Université Paris Diderot-Paris 7, Paris 75013, France
| | - Cláudia Brito
- Group of Molecular Microbiology, IBMC – Institute for Molecular and Cell Biology; i3S – Institute for Research and Innovation in Health, Porto 4200-135, Portugal
- ICBAS- Instituto de Ciências Biomédicas Abel Salazar, University of Porto, Porto 4200-135, Portugal
| | - Anna Pöntinen
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki 00014, Finland
| | - Hannu Korkeala
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki 00014, Finland
| | - Nuno M S dos Santos
- Group of Fish Immunology & Vaccinology, IBMC – Institute for Molecular and Cell Biology; i3S – Institute for Research and Innovation in Health, Porto 4200-135, Portugal
| | - João H Morais-Cabral
- Group of Structural Biochemistry, IBMC – Institute for Molecular and Cell Biology; i3S – Institute for Research and Innovation in Health, Porto 4200-135, Portugal
| | - Sandra Sousa
- Group of Molecular Microbiology, IBMC – Institute for Molecular and Cell Biology; i3S – Institute for Research and Innovation in Health, Porto 4200-135, Portugal
| | - Didier Cabanes
- Group of Molecular Microbiology, IBMC – Institute for Molecular and Cell Biology; i3S – Institute for Research and Innovation in Health, Porto 4200-135, Portugal
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Tanabe T, Isshiki A, Miyamoto K, Tsujibo H, Yamamoto S, Funahashi T. Transcriptional regulation of the ferric aerobactin receptor gene by a GntR-like repressor IutR in Vibrio furnissii. FEMS Microbiol Lett 2018; 365:5092603. [PMID: 30203068 DOI: 10.1093/femsle/fny220] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 09/06/2018] [Indexed: 12/26/2022] Open
Abstract
We found that Vibrio furnissii can utilize aerobactin (AERO) as a xenosiderophore. A homology search of its genome revealed that this bacterium possesses genes encoding an AERO-mediated iron acquisition system similar to that of V. vulnificus. The system consists of the ABC transporter gene vatCDB, the GntR-type transcriptional repressor gene iutR, and the outer membrane receptor gene iutA. The functions of the vatCDB operon and iutA in V. furnissii were confirmed by the inability of the corresponding deletion mutants to utilize AERO. Reverse transcription-quantitative PCR revealed that iutA transcription under iron-limiting conditions was extensively activated by the addition of AERO to the growth medium; therefore, we focused on elucidating this phenomenon. Electrophoretic mobility shift and DNase I footprinting assays revealed that glutathione S-transferase-fused IutR (GST-IutR) bound directly to a specific palindromic sequence in the iutA promoter region. However, GST-IutR did not bind to this sequence when either AERO or ferric AERO was present in the assay mixture. These in vitro findings suggest that, under iron-limiting conditions, iutA transcription in V. furnissii is artfully regulated both by IutR, acting as a direct repressor of iutA, and by AERO, acting as an effector for IutR, leading to the derepression of iutA transcription.
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Affiliation(s)
- Tomotaka Tanabe
- Laboratory of Hygienic Chemistry, College of Pharmaceutical Sciences, Matsuyama University, Matsuyama, 790-8578 Ehime, Japan
| | - Ayaka Isshiki
- Laboratory of Hygienic Chemistry, College of Pharmaceutical Sciences, Matsuyama University, Matsuyama, 790-8578 Ehime, Japan
| | - Katsushiro Miyamoto
- Department of Microbiology, Osaka University of Pharmaceutical Sciences, Takatsuki, 569-1094 Osaka, Japan
| | - Hiroshi Tsujibo
- Department of Microbiology, Osaka University of Pharmaceutical Sciences, Takatsuki, 569-1094 Osaka, Japan
| | - Shigeo Yamamoto
- Laboratory of Hygienic Chemistry, College of Pharmaceutical Sciences, Matsuyama University, Matsuyama, 790-8578 Ehime, Japan
| | - Tatsuya Funahashi
- Laboratory of Hygienic Chemistry, College of Pharmaceutical Sciences, Matsuyama University, Matsuyama, 790-8578 Ehime, Japan
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Woods EC, Edwards AN, Childress KO, Jones JB, McBride SM. The C. difficile clnRAB operon initiates adaptations to the host environment in response to LL-37. PLoS Pathog 2018; 14:e1007153. [PMID: 30125334 PMCID: PMC6117091 DOI: 10.1371/journal.ppat.1007153] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 08/30/2018] [Accepted: 07/16/2018] [Indexed: 01/05/2023] Open
Abstract
To cause disease, Clostridioides (Clostridium) difficile must resist killing by innate immune effectors in the intestine, including the host antimicrobial peptide, cathelicidin (LL-37). The mechanisms that enable C. difficile to adapt to the intestine in the presence of antimicrobial peptides are unknown. Expression analyses revealed an operon, CD630_16170-CD630_16190 (clnRAB), which is highly induced by LL-37 and is not expressed in response to other cell-surface active antimicrobials. This operon encodes a predicted transcriptional regulator (ClnR) and an ABC transporter system (ClnAB), all of which are required for function. Analyses of a clnR mutant indicate that ClnR is a pleiotropic regulator that directly binds to LL-37 and controls expression of numerous genes, including many involved in metabolism, cellular transport, signaling, gene regulation, and pathogenesis. The data suggest that ClnRAB is a novel regulatory mechanism that senses LL-37 as a host signal and regulates gene expression to adapt to the host intestinal environment during infection.
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Affiliation(s)
- Emily C. Woods
- Department of Microbiology and Immunology, and Emory University Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, GA, United States of America
| | - Adrianne N. Edwards
- Department of Microbiology and Immunology, and Emory University Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, GA, United States of America
| | - Kevin O. Childress
- Department of Microbiology and Immunology, and Emory University Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, GA, United States of America
| | - Joshua B. Jones
- Department of Microbiology and Immunology, and Emory University Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, GA, United States of America
| | - Shonna M. McBride
- Department of Microbiology and Immunology, and Emory University Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, GA, United States of America
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Tramonti A, Nardella C, di Salvo ML, Pascarella S, Contestabile R. The MocR-like transcription factors: pyridoxal 5'-phosphate-dependent regulators of bacterial metabolism. FEBS J 2018; 285:3925-3944. [PMID: 29974999 DOI: 10.1111/febs.14599] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 06/14/2018] [Accepted: 06/25/2018] [Indexed: 12/22/2022]
Abstract
Many biological functions played by current proteins were not created by evolution from scratch, rather they were obtained combining already available protein scaffolds. This is the case of MocR-like bacterial transcription factors (MocR-TFs), a subclass of GntR transcription regulators, whose structure is the outcome of the fusion between DNA-binding proteins and pyridoxal 5'-phosphate (PLP)-dependent enzymes. The resultant chimeras can count on the properties of both protein classes, i.e. the capability to recognize specific DNA sequences and to bind PLP and amino-compounds; it is the modulation of such binding properties to confer to MocR-TFs chimeras the ability to interact with effector molecules and DNA so as to regulate transcription. MocR-TFs control different metabolic processes involving vitamin B6 and amino acids, which are canonical ligands of PLP-dependent enzymes. However, MocR-TFs are also implicated in the metabolism of compounds that are not substrates of PLP-dependent enzymes, such as rhizopine and ectoine. Genomic analyses show that MocR-TFs are widespread among eubacteria, implying an essential role in their metabolism and highlighting the scarcity of our knowledge on these important players in microbial metabolism. Although MocR-TFs have been discovered 15 years ago, the research activity on these transcriptional regulators has only recently intensified, producing a wealth of information that needs to be brought back to general principles. This is the main task of this review, which reports and analyses the available information concerning MocR-TFs functional role, structural features, interaction with effector molecules and the characteristics of DNA transcriptional factor-binding sites of MocR-based regulatory systems.
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Affiliation(s)
- Angela Tramonti
- Istituto di Biologia e Patologia Molecolari, Consiglio Nazionale delle Ricerche, Roma, Italy.,Dipartimento di Scienze Biochimiche "A. Rossi Fanelli", Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza Università di Roma, Italy
| | - Caterina Nardella
- Dipartimento di Scienze Biochimiche "A. Rossi Fanelli", Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza Università di Roma, Italy
| | - Martino L di Salvo
- Dipartimento di Scienze Biochimiche "A. Rossi Fanelli", Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza Università di Roma, Italy
| | - Stefano Pascarella
- Dipartimento di Scienze Biochimiche "A. Rossi Fanelli", Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza Università di Roma, Italy
| | - Roberto Contestabile
- Dipartimento di Scienze Biochimiche "A. Rossi Fanelli", Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza Università di Roma, Italy
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Interaction of the GntR-family transcription factor Sll1961 with thioredoxin in the cyanobacterium Synechocystis sp. PCC 6803. Sci Rep 2018; 8:6666. [PMID: 29703909 PMCID: PMC5923263 DOI: 10.1038/s41598-018-25077-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 04/16/2018] [Indexed: 11/23/2022] Open
Abstract
Changes in the redox state of the photosynthetic electron transport chain act as a signal to trigger acclimation responses to environmental cues and thioredoxin has been suggested to work as a key factor connecting the redox change with transcriptional regulation in the cyanobacterium Synechocystis sp. PCC 6803. We screened for redox-dependent transcription factors interacting with thioredoxin M (TrxM) and isolated the GntR-type transcription factor Sll1961 previously reported to be involved in acclimation responses of the photosynthetic machinery. Biochemical analyses using recombinant Sll1961 proteins of wild type and mutants of three cysteine residues, C124, C229 and C307, revealed that an intramolecular disulfide bond is formed between C229 and C307 under oxidizing conditions and TrxM can reduce it by attacking C307. Sll1961 exists in a dimeric form of about 80 kDa both under reducing and oxidizing conditions. C124 can form an intermolecular disulfide bond but it is not essential for dimerization. Based on these observations, tertiary structure models of the Sll1961 homodimer and the Sll1961-TrxM complex were constructed.
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Zhou D, Zhi FJ, Qi MZ, Bai FR, Zhang G, Li JM, Liu H, Chen HT, Lin PF, Tang KQ, Liu W, Jin YP, Wang AH. Brucella induces unfolded protein response and inflammatory response via GntR in alveolar macrophages. Oncotarget 2017; 9:5184-5196. [PMID: 29435171 PMCID: PMC5797042 DOI: 10.18632/oncotarget.23706] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 12/04/2017] [Indexed: 01/18/2023] Open
Abstract
Brucella is an intracellular bacterium that causes the zoonosis brucellosis worldwide. Alveolar macrophages (AM) constitute the main cell target of inhaled Brucella. Brucella thwarts immune surveillance and evokes endoplasmic reticulum (ER) stress to replicate in macrophages via virulence factors. The GntR regulators family was concentrated as an important virulence factor in controlling virulence and intracellular survival of Brucella. However, the detailed underlying mechanism for the host-pathogen interaction is poorly understood. In this study the BSS2_II0438 mutant (ΔGntR) was constructed. The type IV secretion system (T4SS) virulence factor genes (VirB2, VirB6, and VirB8) were down-expression in ΔGntR. ΔGntR could infect and proliferate to high titers in GAMs without a significant difference compared with the parental strain. ΔGntR infection increased the expression of ER stress marker genes GRP78, ATF6, and PERK in the early stages of its intracellular cycle but decreased the expression of these genes in the late stages. ΔGntR increased greatly the number of Brucella CFUs in the inactive ER stress state in GAMs. Meanwhile, ΔGntR infection increased the levels of IFN-γ, IL-1β, and TNF-α, indicating ΔGntR could induce the secretion of inflammatory but not anti-inflammatory cytokines IL-10. Taken together, our results clarified the role of the GntR in B. suis. S2 virulence expression and elucidated that GntR is potentially involved in the signaling pathway of the Brucella-induced UPR and inflammatory response in GAMs.
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Affiliation(s)
- Dong Zhou
- Key Laboratory of Animal Biotechnology of The Ministry of Agriculture, Northwest A&F University, Yangling, China.,College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Fei-Jie Zhi
- Key Laboratory of Animal Biotechnology of The Ministry of Agriculture, Northwest A&F University, Yangling, China.,College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Mao-Zhen Qi
- Key Laboratory of Animal Biotechnology of The Ministry of Agriculture, Northwest A&F University, Yangling, China.,College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Fu-Rong Bai
- Key Laboratory of Animal Biotechnology of The Ministry of Agriculture, Northwest A&F University, Yangling, China.,College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Guangdong Zhang
- Key Laboratory of Animal Biotechnology of The Ministry of Agriculture, Northwest A&F University, Yangling, China.,College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Jun-Mei Li
- Key Laboratory of Animal Biotechnology of The Ministry of Agriculture, Northwest A&F University, Yangling, China.,College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Huan Liu
- Key Laboratory of Animal Biotechnology of The Ministry of Agriculture, Northwest A&F University, Yangling, China.,College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Hua-Tao Chen
- Key Laboratory of Animal Biotechnology of The Ministry of Agriculture, Northwest A&F University, Yangling, China.,College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Peng-Fei Lin
- Key Laboratory of Animal Biotechnology of The Ministry of Agriculture, Northwest A&F University, Yangling, China.,College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Ke-Qiong Tang
- Key Laboratory of Animal Biotechnology of The Ministry of Agriculture, Northwest A&F University, Yangling, China.,College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Wei Liu
- Key Laboratory of Animal Biotechnology of The Ministry of Agriculture, Northwest A&F University, Yangling, China.,College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Ya-Ping Jin
- Key Laboratory of Animal Biotechnology of The Ministry of Agriculture, Northwest A&F University, Yangling, China.,College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Ai-Hua Wang
- College of Veterinary Medicine, Northwest A&F University, Yangling, China
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Milano T, Gulzar A, Narzi D, Guidoni L, Pascarella S. Molecular dynamics simulation unveils the conformational flexibility of the interdomain linker in the bacterial transcriptional regulator GabR from Bacillus subtilis bound to pyridoxal 5'-phosphate. PLoS One 2017; 12:e0189270. [PMID: 29253008 PMCID: PMC5734734 DOI: 10.1371/journal.pone.0189270] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 11/22/2017] [Indexed: 11/18/2022] Open
Abstract
GabR from Bacillus subtilis is a transcriptional regulator belonging to the MocR subfamily of the GntR regulators. The structure of the MocR regulators is characterized by the presence of two domains: i) a N-terminal domain, about 60 residue long, possessing the winged-Helix-Turn-Helix (wHTH) architecture with DNA recognition and binding capability; ii) a C-terminal domain (about 350 residue) folded as the pyridoxal 5'-phosphate (PLP) dependent aspartate aminotransferase (AAT) with dimerization and effector binding functions. The two domains are linked to each other by a peptide bridge. Although structural and functional characterization of MocRs is proceeding at a fast pace, virtually nothing is know about the molecular changes induced by the effector binding and on how these modifications influence the properties of the regulator. An extensive molecular dynamics simulation on the crystallographic structure of the homodimeric B. subtilis GabR has been undertaken with the aim to envisage the role and the importance of conformational flexibility in the action of GabR. Molecular dynamics has been calculated for the apo (without PLP) and holo (with PLP bound) forms of the GabR. A comparison between the molecular dynamics trajectories calculated for the two GabR forms suggested that one of the wHTH domain detaches from the AAT-like domain in the GabR PLP-bound form. The most evident conformational change in the holo PLP-bound form is represented by the rotation and the subsequent detachment from the subunit surface of one of the wHTH domains. The movement is mediated by a rearrangement of the linker connecting the AAT domain possibly triggered by the presence of the negative charge of the PLP cofactor. This is the second most significant conformational modification. The C-terminal section of the linker docks into the "active site" pocket and establish stabilizing contacts consisting of hydrogen-bonds, salt-bridges and hydrophobic interactions.
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Affiliation(s)
- Teresa Milano
- Dipartimento di Scienze biochimiche “A. Rossi Fanelli”, Sapienza Università di Roma, Italy
| | - Adnan Gulzar
- Dipartimento di Scienze Fisiche e Chimiche, Università degli Studi dell’Aquila, L’Aquila, Italy
| | - Daniele Narzi
- Dipartimento di Scienze Fisiche e Chimiche, Università degli Studi dell’Aquila, L’Aquila, Italy
| | - Leonardo Guidoni
- Dipartimento di Scienze Fisiche e Chimiche, Università degli Studi dell’Aquila, L’Aquila, Italy
| | - Stefano Pascarella
- Dipartimento di Scienze biochimiche “A. Rossi Fanelli”, Sapienza Università di Roma, Italy
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A Comprehensive Computational Analysis of Mycobacterium Genomes Pinpoints the Genes Co-occurring with YczE, a Membrane Protein Coding Gene Under the Putative Control of a MocR, and Predicts its Function. Interdiscip Sci 2017; 10:111-125. [PMID: 29098594 DOI: 10.1007/s12539-017-0266-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2017] [Revised: 09/08/2017] [Accepted: 10/11/2017] [Indexed: 10/18/2022]
Abstract
Bacterial proteins belonging to the YczE family are predicted to be membrane proteins of yet unknown function. In many bacterial species, the yczE gene coding for the YczE protein is divergently transcribed with respect to an adjacent transcriptional regulator of the MocR family. According to in silico predictions, proteins named YczR are supposed to regulate the expression of yczE genes. These regulators linked to the yczE genes are predicted to constitute a subfamily within the MocR family. To put forward hypotheses amenable to experimental testing about the possible function of the YczE proteins, a phylogenetic profile strategy was applied. This strategy consists in searching for those genes that, within a set of genomes, co-occur exclusively with a certain gene of interest. Co-occurrence can be suggestive of a functional link. A set of 30 mycobacterial complete proteomes were collected. Of these, only 16 contained YczE proteins. Interestingly, in all cases each yczE gene was divergently transcribed with respect to a yczR gene. Two orthology clustering procedures were applied to find proteins co-occurring exclusively with the YczE proteins. The reported results suggest that YczE may be involved in the membrane translocation and metabolism of sulfur-containing compounds mostly in rapidly growing, low pathogenicity mycobacterial species. These observations may hint at potential targets for therapies to treat the emerging opportunistic infections provoked by the widespread environmental mycobacterial species and may contribute to the delineation of the genomic and physiological differences between the pathogenic and non-pathogenic mycobacterial species.
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Okrent RA, Trippe KM, Maselko M, Manning V. Functional analysis of a biosynthetic cluster essential for production of 4-formylaminooxyvinylglycine, a germination-arrest factor from Pseudomonas fluorescens WH6. MICROBIOLOGY-SGM 2017; 163:207-217. [PMID: 28270265 DOI: 10.1099/mic.0.000418] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Rhizosphere-associated Pseudomonas fluorescens WH6 produces the germination-arrest factor 4-formylaminooxyvinylglycine (FVG). FVG has previously been shown to both arrest the germination of weedy grasses and inhibit the growth of the bacterial plant pathogen Erwinia amylovora. Very little is known about the mechanism by which FVG is produced. Although a previous study identified a region of the genome that may be involved in FVG biosynthesis, it has not yet been determined which genes within that region are sufficient and necessary for FVG production. In the current study, we explored the role of each of the putative genes encoded in that region by constructing deletion mutations. Mutant strains were assayed for their ability to produce FVG with a combination of biological assays and TLC analyses. This work defined the core FVG biosynthetic gene cluster and revealed several interesting characteristics of FVG production. We determined that FVG biosynthesis requires two small ORFs of less than 150 nucleotides and that multiple transporters have overlapping but distinct functionality. In addition, two genes in the centre of the biosynthetic gene cluster are not required for FVG production, suggesting that additional products may be produced from the cluster. Transcriptional analysis indicated that at least three active promoters play a role in the expression of genes within this cluster. The results of this study enrich our knowledge regarding the diversity of mechanisms by which bacteria produce non-proteinogenic amino acids like vinylglycines.
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Affiliation(s)
- Rachel A Okrent
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR, USA.,USDA-ARS Forage Seed and Cereal Research Unit, Corvallis, OR, USA
| | - Kristin M Trippe
- Department of Crop and Soil Science, Oregon State University, Corvallis, OR, USA.,USDA-ARS Forage Seed and Cereal Research Unit, Corvallis, OR, USA
| | - Maciej Maselko
- Present address: Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, St. Paul, MN, USA.,USDA-ARS Forage Seed and Cereal Research Unit, Corvallis, OR, USA
| | - Viola Manning
- USDA-ARS Forage Seed and Cereal Research Unit, Corvallis, OR, USA
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Role of GntR Family Regulatory Gene SCO1678 in Gluconate Metabolism in Streptomyces coelicolor M145. BIOMED RESEARCH INTERNATIONAL 2017; 2017:9529501. [PMID: 28536705 PMCID: PMC5425828 DOI: 10.1155/2017/9529501] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/02/2017] [Revised: 03/07/2017] [Accepted: 03/26/2017] [Indexed: 11/19/2022]
Abstract
Here we report functional characterization of the Streptomyces coelicolor M145 gene SCO1678, which encodes a GntR-like regulator of the FadR subfamily. Bioinformatic analysis suggested that SCO1678 is part of putative operon (gnt) involved in gluconate metabolism. Combining the results of SCO1678 knockout, transcriptional analysis of gnt operon, and Sco1678 protein-DNA electromobility shift assays, we established that Sco1678 protein controls the gluconate operon. It does so via repression of its transcription from a single promoter located between genes SCO1678 and SCO1679. The knockout also influenced, in a medium-dependent manner, the production of secondary metabolites by S. coelicolor. In comparison to the wild type, on gluconate-containing minimal medium, the SCO1678 mutant produced much less actinorhodin and accumulated a yellow-colored pigment, likely to be the cryptic polyketide coelimycin. Possible links between gluconate metabolism and antibiotic production are discussed.
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