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Gaddy KE, Bensch EM, Cavanagh J, Milton ME. Insights into DNA-binding motifs and mechanisms of Francisella tularensis novicida two-component system response regulator proteins QseB, KdpE, and BfpR. Biochem Biophys Res Commun 2024; 722:150150. [PMID: 38805787 DOI: 10.1016/j.bbrc.2024.150150] [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: 03/06/2024] [Revised: 05/09/2024] [Accepted: 05/20/2024] [Indexed: 05/30/2024]
Abstract
Two component system bacterial response regulators are typically DNA-binding proteins which enable the genetic regulation of many adaptive bacterial behaviors. Despite structural similarity across response regulator families, there is a diverse array of DNA-binding mechanisms. Bacteria usually encode several dozen two-component system response regulators, but Francisella tularensis only encodes three. Due to their simplified response regulatory network, Francisella species are a model for studying the role of response regulator proteins in virulence. Here, we show that Francisella response regulators QseB, KdpE, and BfpR all utilize different DNA-binding mechanisms. Our evidence suggests that QseB follows a simple mechanism whereby it binds a single inverted repeat sequence with a higher affinity upon phosphorylation. This behavior is independent of whether QseB is a positive or negative regulator of the gene as demonstrated by qseB and priM promoter sequences, respectively. Similarly, KdpE binds DNA more tightly upon phosphorylation, but also exhibits a cooperative binding isotherm. While we propose a KdpE binding site, it is possible that KdpE has a complex DNA-binding mechanism potentially involving multiple copies of KdpE being recruited to a promoter region. Finally, we show that BfpR appears to bind a region of its own promoter sequence with a lower affinity upon phosphorylation. Further structural and enzymatic work will need to be performed to deconvolute the KdpE and BfpR binding mechanisms.
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Affiliation(s)
- Keegan E Gaddy
- Department of Biochemistry and Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, NC, USA
| | - Elody M Bensch
- Department of Biochemistry and Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, NC, USA
| | - John Cavanagh
- Department of Biochemistry and Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, NC, USA
| | - Morgan E Milton
- Department of Biochemistry and Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, NC, USA.
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2
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Raustad N, Dai Y, Iinishi A, Mohapatra A, Soo MW, Hay E, Hernandez GM, Geisinger E. A phosphorylation signal activates genome-wide transcriptional control by BfmR, the global regulator of Acinetobacter resistance and virulence. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.16.599214. [PMID: 38948834 PMCID: PMC11212878 DOI: 10.1101/2024.06.16.599214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
The nosocomial pathogen Acinetobacter baumannii is a major threat to human health. The sensor kinase-response regulator system, BfmS-BfmR, is essential to multidrug resistance and virulence in the bacterium and represents a potential antimicrobial target. Important questions remain about how the system controls resistance and pathogenesis. Although BfmR knockout alters expression of >1000 genes, its direct regulon is undefined. Moreover, how phosphorylation controls the regulator is unclear. Here, we address these problems by combining mutagenesis, ChIP-seq, and in vitro phosphorylation to study the functions of phospho-BfmR. We show that phosphorylation is required for BfmR-mediated gene regulation, antibiotic resistance, and sepsis development in vivo. Consistent with activating the protein, phosphorylation induces dimerization and target DNA affinity. Integrated analysis of genome-wide binding and transcriptional profiles of BfmR led to additional key findings: (1) Phosphorylation dramatically expands the number of genomic sites BfmR binds; (2) DNA recognition involves a direct repeat motif widespread across promoters; (3) BfmR directly regulates 303 genes as activator (eg, capsule, peptidoglycan, and outer membrane biogenesis) or repressor (pilus biogenesis); (4) BfmR controls several non-coding sRNAs. These studies reveal the centrality of a phosphorylation signal in driving A. baumannii disease and disentangle the extensive pathogenic gene-regulatory network under its control.
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Affiliation(s)
- Nicole Raustad
- Department of Biology, Northeastern University, Boston, MA 02115, USA
| | - Yunfei Dai
- Department of Biology, Northeastern University, Boston, MA 02115, USA
| | - Akira Iinishi
- Antimicrobial Discovery Center, Department of Biology, Northeastern University, Boston, MA 02115, USA
| | - Arpita Mohapatra
- Department of Biology, Northeastern University, Boston, MA 02115, USA
| | - Mark W. Soo
- Department of Biology, Northeastern University, Boston, MA 02115, USA
| | - Everett Hay
- Department of Biology, Northeastern University, Boston, MA 02115, USA
| | | | - Edward Geisinger
- Department of Biology, Northeastern University, Boston, MA 02115, USA
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3
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Cao M, Wang F, Ma S, Bashir S, Liu S, Sun K, Xing B. Deciphering the Impact of ZnO Nanoparticles and a Sunscreen Product Containing ZnO on Phosphorus Dynamics and Release in Chlorella pyrenoidosa in Aquatic Systems. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:10262-10274. [PMID: 38809112 DOI: 10.1021/acs.est.4c01126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2024]
Abstract
Zinc oxide nanoparticles (ZnO NPs) expedite the conversion of organic phosphorus (OP) into PO4-P (Pi), facilitating phosphorus (P) absorption by algae. Our study explored the mechanisms of converting OP (2-aminoethylphosphonic acid (AEP) and β-glycerol phosphate (β-GP)) into Pi in Chlorella pyrenoidosa under P deficiency with sunscreen and ZnO NPs. Cell density followed the order of K2HPO4 > β-GP+ZnO > β-GP > AEP+ZnO > AEP > P-free. ZnO NPs promoted the conversion of β-GP, containing C-O-P bonds (0.028-0.041 mg/L), into Pi more efficiently than AEP, which possesses C-P bonds (0.022-0.037 mg/L). Transcriptomics revealed Pi transport/metabolism (phoB (3.99-12.01 fold), phoR (2.20-5.50 fold), ppa (4.49-10.40 fold), and ppk (2.50-5.40 fold)) and phospholipid metabolism (SQD1 (1.85-2.79 fold), SQD2 (2.60-6.53 fold), MGD (2.13-3.21 fold), and DGD (4.08-7.56 fold)) were up-regulated compared to K2HPO4. 31P nuclear magnetic resonance spectroscopy identified intracellular P as polyphosphate, orthophosphate, and pyrophosphate. Synchrotron radiation-based X-ray near-edge structure spectroscopy indicated that K2HPO4 and Zn3(PO4)2 in β-GP+ZnO were increased by 8.09% and 7.28% compared to AEP+ZnO, suggesting superior P storage in β-GP+ZnO. Overall, ZnO NPs improved photoinduced electron-hole pair separation and charge separation efficiency and amplified the ·OH and ·O2- levels, promoting OP photoconversion into Pi and algae growth.
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Affiliation(s)
- Manman Cao
- School of Environment, Beijing Normal University, 19 Xinjiekouwai Street Beijing 100875, China
| | - Fei Wang
- School of Environment, Beijing Normal University, 19 Xinjiekouwai Street Beijing 100875, China
| | - Shuai Ma
- School of Environment, Beijing Normal University, 19 Xinjiekouwai Street Beijing 100875, China
| | - Safdar Bashir
- Department of Soil and Environmental Sciences, Ghazi University, Dera Ghazi Khan 32000, Pakistan
| | - Shuhu Liu
- Laboratory of Synchrotron Radiation, Institute of High Energy Physics, The Chinese Academy of Sciences, Beijing 100039, China
| | - Ke Sun
- School of Environment, Beijing Normal University, 19 Xinjiekouwai Street Beijing 100875, China
| | - Baoshan Xing
- Stockbridge School of Agriculture, University of Massachusetts, Amherst Massachusetts 01003, United States
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Cai X, Yang S, Peng Y, Tan K, Xu P, Wu Z, Kwan KY, Jian J. Regulation of PhoB on biofilm formation and hemolysin gene hlyA and ciaR of Streptococcus agalactiae. Vet Microbiol 2024; 289:109961. [PMID: 38147806 DOI: 10.1016/j.vetmic.2023.109961] [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: 06/17/2023] [Revised: 12/08/2023] [Accepted: 12/19/2023] [Indexed: 12/28/2023]
Abstract
PhoB is a response regulator protein that plays a key role in the PhoBR two-component signal transduction system. In this study, we used transcriptome and proteomics techniques to evaluate the detect the gene network regulated by PhoB of Streptococcus agalactiae. The results showed that expression of biofilm formation and virulence-related genes were changed after phoB deficiency. Crystal violet and CLSM assay confirmed that the deletion of the phoB increased the thickness of S. agalactiae biofilm. The results of lacZ reporter and the bacterial one-hybridization method showed that PhoB could directly bind to the promoter regions of hemolysin A and ciaR genes but not to the promoter regions of cylE and hemolysin III. Through the construction of an 18-base pair deoxyribose nucleic acid (DNA) random fragment library and the bacterial one-hybridization system, it was found that the conservative sequence of PhoB binding was TTGGAGAA(G/T). Our research has uncovered the virulence potential of the PhoBR two-component system of S. agalactiae. The findings of this study provide the theoretical foundation for in-depth research on the pathogenic mechanism of S. agalactiae.
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Affiliation(s)
- Xiaohui Cai
- Guangxi Key Laboratory of Beibu Gulf Marine Biodiversity Conservation, Ocean College, Beibu Gulf University, Qinzhou 535011, China
| | - Shaoyu Yang
- Guangxi Key Laboratory of Beibu Gulf Marine Biodiversity Conservation, Ocean College, Beibu Gulf University, Qinzhou 535011, China
| | - Yinhui Peng
- Guangxi Key Laboratory of Beibu Gulf Marine Biodiversity Conservation, Ocean College, Beibu Gulf University, Qinzhou 535011, China; College of Fishery, Guangdong Ocean University, Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animal, Key Laboratory of Control for Disease of Aquatic Animals of Guangdong Higher Education Institutes, Southern Marine Science and Engineering Guangdong Laboratory, Zhanjiang 524088, China
| | - Kianann Tan
- Guangxi Key Laboratory of Beibu Gulf Marine Biodiversity Conservation, Ocean College, Beibu Gulf University, Qinzhou 535011, China
| | - Peng Xu
- Guangxi Key Laboratory of Beibu Gulf Marine Biodiversity Conservation, Ocean College, Beibu Gulf University, Qinzhou 535011, China
| | - Zaohe Wu
- College of Fishery, Guangdong Ocean University, Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animal, Key Laboratory of Control for Disease of Aquatic Animals of Guangdong Higher Education Institutes, Southern Marine Science and Engineering Guangdong Laboratory, Zhanjiang 524088, China
| | - Kit Yue Kwan
- Guangxi Key Laboratory of Beibu Gulf Marine Biodiversity Conservation, Ocean College, Beibu Gulf University, Qinzhou 535011, China.
| | - Jichang Jian
- College of Fishery, Guangdong Ocean University, Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animal, Key Laboratory of Control for Disease of Aquatic Animals of Guangdong Higher Education Institutes, Southern Marine Science and Engineering Guangdong Laboratory, Zhanjiang 524088, China.
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Freire IR, Bensig EO, Kuang Z, MacLellan SR. Analysis of CenKR essentiality in Sinorhizobium meliloti and its activity at a target gene promoter in vivo. FEMS Microbiol Lett 2024; 371:fnae061. [PMID: 39066494 PMCID: PMC11328730 DOI: 10.1093/femsle/fnae061] [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: 04/20/2024] [Revised: 06/27/2024] [Accepted: 07/25/2024] [Indexed: 07/28/2024] Open
Abstract
The two-component regulatory system CenK-CenR has recently emerged as a regulator of cell envelope and cell division processes in the alpha-proteobacteria. In Sinorhizobium meliloti, CenK-CenR regulates the expression of SrlA, a thioredoxin-domain protein of unknown function. Deletion of srlA causes sensitivity to salt and oxidizing agents on solid growth medium. In this work, we report that the response regulator CenR, but not the histidine kinase CenK, is essential for cell viability in S. meliloti. We also demonstrate that phosphorylation of the target residue D55 is not required for viability, suggesting that the unphosphorylated transcription factor sufficiently regulates expression of one or more essential genes in the genome. Using transcription assays and phenotype testing we examine CenK-CenR-dependent activation of the srlA promoter and demonstrate its absolute dependence on phosphoryl-CenR for activity and that the CenR substitution D55E acts as a phosphomimetic that partially restores activity at the srlA promoter in the absence of phosphorylation by CenK. Finally, we report a mutational analysis of the CenR binding site in the srlA promoter required for transcriptional activation.
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Affiliation(s)
- Isabela R Freire
- Department of Biology, University of New Brunswick, Fredericton, New Brunswick, Canada
| | - Eukene O Bensig
- Department of Biology and Environmental Science, University of the Philippines Cebu, Cebu City, Philippines
| | - ZiYu Kuang
- Department of Biology, University of New Brunswick, Fredericton, New Brunswick, Canada
| | - Shawn R MacLellan
- Department of Biology, University of New Brunswick, Fredericton, New Brunswick, Canada
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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: 1] [Impact Index Per Article: 1.0] [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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Memon AA, Fu X, Fan XY, Xu L, Xiao J, Rahman MU, Yang X, Yao YF, Deng Z, Ma W. Substrate DNA Promoting Binding of Mycobacterium tuberculosis MtrA by Facilitating Dimerization and Interpretation of Affinity by Minor Groove Width. Microorganisms 2023; 11:2505. [PMID: 37894163 PMCID: PMC10609481 DOI: 10.3390/microorganisms11102505] [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: 08/07/2023] [Revised: 09/21/2023] [Accepted: 09/28/2023] [Indexed: 10/29/2023] Open
Abstract
In order to deepen the understanding of the role and regulation mechanisms of prokaryotic global transcription regulators in complex processes, including virulence, the associations between the affinity and binding sequences of Mycobacterium tuberculosis MtrA have been explored extensively. Analysis of MtrA 294 diversified 26 bp binding sequences revealed that the sequence similarity of fragments was not simply associated with affinity. The unique variation patterns of GC content and periodical and sequential fluctuation of affinity contribution curves were observed along the sequence in this study. Furthermore, docking analysis demonstrated that the structure of the dimer MtrA-DNA (high affinity) was generally consistent with other OmpR family members, while Arg 219 and Gly 220 of the wing domain interacted with the minor groove. The results of the binding box replacement experiment proved that box 2 was essential for binding, which implied the differential roles of the two boxes in the binding process. Furthermore, the results of the substitution of the nucleotide at the 20th and/or 21st positions indicated that the affinity was negatively associated with the value of minor groove width precisely at the 21st position. The dimerization of the unphosphorylated MtrA facilitated by a low-affinity DNA fragment was observed for the first time. However, the proportion of the dimer was associated with the affinity of substrate DNA, which further suggested that the affinity was actually one characteristic of the stability of dimers. Based on the finding of 17 inter-molecule hydrogen bonds identified in the interface of the MtrA dimer, including 8 symmetric complementary ones in the conserved α4-β5-α5 face, we propose that hydrogen bonds should be considered just as important as salt bridges and the hydrophobic patch in the dimerization. Our comprehensive study on a large number of binding fragments with quantitative affinity values provided new insight into the molecular mechanism of dimerization, binding specificity and affinity determination of MtrA and clues for solving the puzzle of how global transcription factors regulate a large quantity of target genes.
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Affiliation(s)
- Aadil Ahmed Memon
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Xiang Fu
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Xiao-Yong Fan
- Shanghai Institute of Infectious Diseases and Biosecurity, Shanghai Public Health Clinical Center, Fudan University, Shanghai 200032, China
| | - Lingyun Xu
- Shanghai Huaxin Biotechnology Co., Ltd., Room 604, Building 1, Tongji Chuangyuan, No. 99 South Changjiang Road, Baoshan District, Shanghai 200441, China
| | - Jihua Xiao
- Shanghai Huaxin Biotechnology Co., Ltd., Room 604, Building 1, Tongji Chuangyuan, No. 99 South Changjiang Road, Baoshan District, Shanghai 200441, China
| | - Mueed Ur Rahman
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Xiaoqi Yang
- Shanghai Huaxin Biotechnology Co., Ltd., Room 604, Building 1, Tongji Chuangyuan, No. 99 South Changjiang Road, Baoshan District, Shanghai 200441, China
| | - Yu-Feng Yao
- Laboratory of Bacterial Pathogenesis, Institutes of Medical Sciences, School of Medicine, Shanghai Jiao Tong University, Shanghai 200025, China
| | - Zixin Deng
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Wei Ma
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
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Castillo-Zeledón A, Rivas-Solano O, Villalta-Romero F, Gómez-Espinoza O, Moreno E, Chaves-Olarte E, Guzmán-Verri C. The Brucella abortus two-component system response regulator BvrR binds to three DNA regulatory boxes in the upstream region of omp25. Front Microbiol 2023; 14:1241143. [PMID: 37779712 PMCID: PMC10538546 DOI: 10.3389/fmicb.2023.1241143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 08/15/2023] [Indexed: 10/03/2023] Open
Abstract
Brucella abortus is a facultative extracellular-intracellular bacterial zoonotic pathogen worldwide. It is also a major cause of abortion in bovines, generating economic losses. The two-component regulatory system BvrR/BvrS modulates the expression of genes required to transition from extracellular to intracellular lifestyles. However, few regulatory regions of BvrR direct target genes have been studied. In this study, we characterized the regulatory region of omp25, a gene encoding an outer membrane protein that is positively regulated by TCS BvrR/BvrS. By omp25-lacZ reporter fusions and β-galactosidase activity assays, we found that the region between-262 and + 127 is necessary for transcriptional activity, particularly a 111-bp long fragment located from-262 to -152. In addition, we demonstrated the binding of P-BvrR to three sites within the -140 to +1 region. Two of these sites were delimited between -18 to +1 and - 99 to -76 by DNase I footprinting and called DNA regulatory boxes 1 and 2, respectively. The third binding site (box 3) was delimited from -140 to -122 by combining EMSA and fluorescence anisotropy results. A molecular docking analysis with HDOCK predicted BvrR-DNA interactions between 11, 13, and 12 amino acid residue-nucleotide pairs in boxes 1, 2, and 3, respectively. A manual sequence alignment of the three regulatory boxes revealed the presence of inverted and non-inverted repeats of five to eight nucleotides, partially matching DNA binding motifs previously described for BvrR. We propose that P-BvrR binds directly to up to three regulatory boxes and probably interacts with other transcription factors to regulate omp25 expression. This gene regulation model could apply to other BvrR target genes and to orthologs of the TCS BvrR/BvrS and Omp25 in phylogenetically closed Rhizobiales.
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Affiliation(s)
- Amanda Castillo-Zeledón
- Programa de Investigación en Enfermedades Tropicales, Escuela de Medicina Veterinaria, Universidad Nacional de Costa Rica, Heredia, Costa Rica
| | - Olga Rivas-Solano
- Programa de Investigación en Enfermedades Tropicales, Escuela de Medicina Veterinaria, Universidad Nacional de Costa Rica, Heredia, Costa Rica
- Centro de Investigación en Biotecnología, Escuela de Biología, Instituto Tecnológico de Costa Rica, Campus Tecnológico Central Cartago, Cartago, Costa Rica
| | - Fabián Villalta-Romero
- Centro de Investigación en Biotecnología, Escuela de Biología, Instituto Tecnológico de Costa Rica, Campus Tecnológico Central Cartago, Cartago, Costa Rica
| | - Olman Gómez-Espinoza
- Centro de Investigación en Biotecnología, Escuela de Biología, Instituto Tecnológico de Costa Rica, Campus Tecnológico Central Cartago, Cartago, Costa Rica
| | - Edgardo Moreno
- Programa de Investigación en Enfermedades Tropicales, Escuela de Medicina Veterinaria, Universidad Nacional de Costa Rica, Heredia, Costa Rica
| | - Esteban Chaves-Olarte
- Centro de Investigación en Enfermedades Tropicales, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | - Caterina Guzmán-Verri
- Programa de Investigación en Enfermedades Tropicales, Escuela de Medicina Veterinaria, Universidad Nacional de Costa Rica, Heredia, Costa Rica
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9
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Rieger J, Fitz M, Fischer SM, Wallmeroth N, Flores-Romero H, Fischer NM, Brand LH, García-Sáez AJ, Berendzen KW, Mira-Rodado V. Exploring the Binding Affinity of the ARR2 GARP DNA Binding Domain via Comparative Methods. Genes (Basel) 2023; 14:1638. [PMID: 37628689 PMCID: PMC10454580 DOI: 10.3390/genes14081638] [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: 07/19/2023] [Revised: 08/01/2023] [Accepted: 08/07/2023] [Indexed: 08/27/2023] Open
Abstract
Plants have evolved signaling mechanisms such as the multi-step phosphorelay (MSP) to respond to different internal and external stimuli. MSP responses often result in gene transcription regulation that is modulated through transcription factors such as B-type Arabidopsis response regulator (ARR) proteins. Among these proteins, ARR2 is a key component that is expressed ubiquitously and is involved in many aspects of plant development. Although it has been noted that B-type ARRs bind to their cognate genes through a DNA-binding domain termed the GARP domain, little is known about the structure and function of this type of DNA-binding domain; thus, how ARRs bind to DNA at a structural level is still poorly understood. In order to understand how the MSP functions in planta, it is crucial to unravel both the kinetics as well as the structural identity of the components involved in such interactions. For this reason, this work focusses on resolving how the GARP domain of ARR2 (GARP2) binds to the promoter region of ARR5, one of its native target genes in cytokinin signaling. We have established that GARP2 specifically binds to the ARR5 promoter with three different bi-molecular interaction systems-qDPI-ELISA, FCS, and MST-and we also determined the KD of this interaction. In addition, structural modeling of the GARP2 domain confirms that GARP2 entails a HTH motif, and that protein-DNA interaction most likely occurs via the α3-helix and the N-terminal arm of this domain since mutations in this region hinder ARR2's ability to activate transcription.
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Affiliation(s)
- Janine Rieger
- Center for Plant Molecular Biology (ZMBP), Tübingen University, 72076 Tübingen, Germany
| | - Michael Fitz
- Center for Plant Molecular Biology (ZMBP), Tübingen University, 72076 Tübingen, Germany
| | - Stefan Markus Fischer
- Center for Plant Molecular Biology (ZMBP), Tübingen University, 72076 Tübingen, Germany
| | - Niklas Wallmeroth
- Center for Plant Molecular Biology (ZMBP), Tübingen University, 72076 Tübingen, Germany
| | - Hector Flores-Romero
- Interfaculty Institute of Biochemistry (IFIB), Tübingen University, 72076 Tübingen, Germany
- CECAD Research Center, Institute of Genetics, Cologne University, 51069 Cologne, Germany
| | - Nina Monika Fischer
- Institute for Bioinformatics and Medical Informatics, Tübingen University, 72076 Tübingen, Germany
| | - Luise Helene Brand
- Center for Plant Molecular Biology (ZMBP), Tübingen University, 72076 Tübingen, Germany
| | - Ana J. García-Sáez
- Interfaculty Institute of Biochemistry (IFIB), Tübingen University, 72076 Tübingen, Germany
- CECAD Research Center, Institute of Genetics, Cologne University, 51069 Cologne, Germany
| | | | - Virtudes Mira-Rodado
- Center for Plant Molecular Biology (ZMBP), Tübingen University, 72076 Tübingen, Germany
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10
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Canals A, Pieretti S, Muriel-Masanes M, El Yaman N, Plecha SC, Thomson JJ, Fàbrega-Ferrer M, Pérez-Luque R, Krukonis ES, Coll M. ToxR activates the Vibrio cholerae virulence genes by tethering DNA to the membrane through versatile binding to multiple sites. Proc Natl Acad Sci U S A 2023; 120:e2304378120. [PMID: 37428913 PMCID: PMC10629549 DOI: 10.1073/pnas.2304378120] [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: 03/17/2023] [Accepted: 05/31/2023] [Indexed: 07/12/2023] Open
Abstract
ToxR, a Vibrio cholerae transmembrane one-component signal transduction factor, lies within a regulatory cascade that results in the expression of ToxT, toxin coregulated pilus, and cholera toxin. While ToxR has been extensively studied for its ability to activate or repress various genes in V. cholerae, here we present the crystal structures of the ToxR cytoplasmic domain bound to DNA at the toxT and ompU promoters. The structures confirm some predicted interactions, yet reveal other unexpected promoter interactions with implications for other potential regulatory roles for ToxR. We show that ToxR is a versatile virulence regulator that recognizes diverse and extensive, eukaryotic-like regulatory DNA sequences, that relies more on DNA structural elements than specific sequences for binding. Using this topological DNA recognition mechanism, ToxR can bind both in tandem and in a twofold inverted-repeat-driven manner. Its regulatory action is based on coordinated multiple binding to promoter regions near the transcription start site, which can remove the repressing H-NS proteins and prepares the DNA for optimal interaction with the RNA polymerase.
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Affiliation(s)
- Albert Canals
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, 08028Barcelona, Spain
- Institut de Biologia Molecular de Barcelona, Consejo Superior de Investigaciones Científicas, 08028Barcelona, Spain
| | - Simone Pieretti
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, 08028Barcelona, Spain
- Institut de Biologia Molecular de Barcelona, Consejo Superior de Investigaciones Científicas, 08028Barcelona, Spain
| | - Mireia Muriel-Masanes
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, 08028Barcelona, Spain
- Institut de Biologia Molecular de Barcelona, Consejo Superior de Investigaciones Científicas, 08028Barcelona, Spain
| | - Nour El Yaman
- Department of Biology, University of Detroit Mercy, Detroit, MI48221
| | - Sarah C. Plecha
- Division of Integrated Biomedical Sciences, University of Detroit Mercy School of Dentistry, Detroit, MI48208
| | - Joshua J. Thomson
- Division of Integrated Biomedical Sciences, University of Detroit Mercy School of Dentistry, Detroit, MI48208
| | - Montserrat Fàbrega-Ferrer
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, 08028Barcelona, Spain
- Institut de Biologia Molecular de Barcelona, Consejo Superior de Investigaciones Científicas, 08028Barcelona, Spain
| | - Rosa Pérez-Luque
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, 08028Barcelona, Spain
- Institut de Biologia Molecular de Barcelona, Consejo Superior de Investigaciones Científicas, 08028Barcelona, Spain
| | - Eric S. Krukonis
- Division of Integrated Biomedical Sciences, University of Detroit Mercy School of Dentistry, Detroit, MI48208
| | - Miquel Coll
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, 08028Barcelona, Spain
- Institut de Biologia Molecular de Barcelona, Consejo Superior de Investigaciones Científicas, 08028Barcelona, Spain
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11
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Fitzgerald DM, Stringer AM, Smith C, Lapierre P, Wade JT. Genome-Wide Mapping of the Escherichia coli PhoB Regulon Reveals Many Transcriptionally Inert, Intragenic Binding Sites. mBio 2023; 14:e0253522. [PMID: 37067422 PMCID: PMC10294691 DOI: 10.1128/mbio.02535-22] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Accepted: 03/23/2023] [Indexed: 04/18/2023] Open
Abstract
Genome-scale analyses have revealed many transcription factor binding sites within, rather than upstream of, genes, raising questions as to the function of these binding sites. Here, we use complementary approaches to map the regulon of the Escherichia coli transcription factor PhoB, a response regulator that controls transcription of genes involved in phosphate homeostasis. Strikingly, the majority of PhoB binding sites are located within genes, but these intragenic sites are not associated with detectable transcription regulation and are not evolutionarily conserved. Many intragenic PhoB sites are located in regions bound by H-NS, likely due to shared sequence preferences of PhoB and H-NS. However, these PhoB binding sites are not associated with transcription regulation even in the absence of H-NS. We propose that for many transcription factors, including PhoB, binding sites not associated with promoter sequences are transcriptionally inert and hence are tolerated as genomic "noise." IMPORTANCE Recent studies have revealed large numbers of transcription factor binding sites within the genes of bacteria. The function, if any, of the vast majority of these binding sites has not been investigated. Here, we map the binding of the transcription factor PhoB across the Escherichia coli genome, revealing that the majority of PhoB binding sites are within genes. We show that PhoB binding sites within genes are not associated with regulation of the overlapping genes. Indeed, our data suggest that bacteria tolerate the presence of large numbers of nonregulatory, intragenic binding sites for transcription factors and that these binding sites are not under selective pressure.
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Affiliation(s)
- Devon M. Fitzgerald
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
- Department of Biomedical Sciences, School of Public Health, University at Albany, Albany, New York, USA
| | - Anne M. Stringer
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - Carol Smith
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - Pascal Lapierre
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - Joseph T. Wade
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
- Department of Biomedical Sciences, School of Public Health, University at Albany, Albany, New York, USA
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12
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Shi J, Feng Z, Xu J, Li F, Zhang Y, Wen A, Wang F, Song Q, Wang L, Cui H, Tong S, Chen P, Zhu Y, Zhao G, Wang S, Feng Y, Lin W. Structural insights into the transcription activation mechanism of the global regulator GlnR from actinobacteria. Proc Natl Acad Sci U S A 2023; 120:e2300282120. [PMID: 37216560 PMCID: PMC10235972 DOI: 10.1073/pnas.2300282120] [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: 01/06/2023] [Accepted: 04/27/2023] [Indexed: 05/24/2023] Open
Abstract
In actinobacteria, an OmpR/PhoB subfamily protein called GlnR acts as an orphan response regulator and globally coordinates the expression of genes responsible for nitrogen, carbon, and phosphate metabolism in actinobacteria. Although many researchers have attempted to elucidate the mechanisms of GlnR-dependent transcription activation, progress is impeded by lacking of an overall structure of GlnR-dependent transcription activation complex (GlnR-TAC). Here, we report a co-crystal structure of the C-terminal DNA-binding domain of GlnR (GlnR_DBD) in complex with its regulatory cis-element DNA and a cryo-EM structure of GlnR-TAC which comprises Mycobacterium tuberculosis RNA polymerase, GlnR, and a promoter containing four well-characterized conserved GlnR binding sites. These structures illustrate how four GlnR protomers coordinate to engage promoter DNA in a head-to-tail manner, with four N-terminal receiver domains of GlnR (GlnR-RECs) bridging GlnR_DBDs and the RNAP core enzyme. Structural analysis also unravels that GlnR-TAC is stabilized by complex protein-protein interactions between GlnR and the conserved β flap, σAR4, αCTD, and αNTD domains of RNAP, which are further confirmed by our biochemical assays. Taken together, these results reveal a global transcription activation mechanism for the master regulator GlnR and other OmpR/PhoB subfamily proteins and present a unique mode of bacterial transcription regulation.
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Affiliation(s)
- Jing Shi
- Department of Pathogen Biology, School of Medicine and Holistic Integrative Medicine, Nanjing University of Chinese Medicine, 210023Nanjing, China
- Department of Biophysics, Zhejiang University School of Medicine, 310058Hangzhou, China
- Department of Infectious Disease of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, 310058Hangzhou, China
| | - Zhenzhen Feng
- Department of Pathogen Biology, School of Medicine and Holistic Integrative Medicine, Nanjing University of Chinese Medicine, 210023Nanjing, China
| | - Juncao Xu
- Key Laboratory of Synthetic Biology, Chinese Academy of Sciences (CAS) Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, 200032Shanghai, China
| | - Fangfang Li
- Department of Pathogen Biology, School of Medicine and Holistic Integrative Medicine, Nanjing University of Chinese Medicine, 210023Nanjing, China
| | - Yuqiong Zhang
- MOE Key Laboratory of Laser Life Science and Institute of Laser Life Science, College of Biophotonics, South China Normal University, 510631Guangzhou, Guangdong, China
- Guangdong Key Laboratory of Laser Life Science, College of Biophotonics, South China Normal University, 510631Guangzhou, Guangdong, China
- Songshan Lake Materials Laboratory, 523808Dongguan, Guangdong, China
| | - Aijia Wen
- Department of Biophysics, Zhejiang University School of Medicine, 310058Hangzhou, China
- Department of Infectious Disease of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, 310058Hangzhou, China
| | - Fulin Wang
- Department of Pathogen Biology, School of Medicine and Holistic Integrative Medicine, Nanjing University of Chinese Medicine, 210023Nanjing, China
| | - Qian Song
- Department of Pathogen Biology, School of Medicine and Holistic Integrative Medicine, Nanjing University of Chinese Medicine, 210023Nanjing, China
| | - Lu Wang
- Department of Pathogen Biology, School of Medicine and Holistic Integrative Medicine, Nanjing University of Chinese Medicine, 210023Nanjing, China
| | - Hong Cui
- Pasteurien College, Suzhou Medical College of Soochow University, Soochow University, 251000Soochow, China
| | - Shujuan Tong
- Department of Pathogen Biology, School of Medicine and Holistic Integrative Medicine, Nanjing University of Chinese Medicine, 210023Nanjing, China
| | - Peiying Chen
- Department of Pathogen Biology, School of Medicine and Holistic Integrative Medicine, Nanjing University of Chinese Medicine, 210023Nanjing, China
| | - Yejin Zhu
- Department of Pathogen Biology, School of Medicine and Holistic Integrative Medicine, Nanjing University of Chinese Medicine, 210023Nanjing, China
| | - Guoping Zhao
- Key Laboratory of Synthetic Biology, Chinese Academy of Sciences (CAS) Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, 200032Shanghai, China
| | - Shuang Wang
- Songshan Lake Materials Laboratory, 523808Dongguan, Guangdong, China
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, 100190Beijing, China
| | - Yu Feng
- Department of Biophysics, Zhejiang University School of Medicine, 310058Hangzhou, China
- Department of Infectious Disease of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, 310058Hangzhou, China
| | - Wei Lin
- Department of Pathogen Biology, School of Medicine and Holistic Integrative Medicine, Nanjing University of Chinese Medicine, 210023Nanjing, China
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai200237, China
- Nanjing Drum Tower Hospital Clinical College, Nanjing University of Chinese Medicine, 210023Nanjing, China
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13
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Ugwu DI, Conradie J. Metal complexes derived from bidentate ligands: Synthesis, catalytic and biological applications. Inorganica Chim Acta 2023. [DOI: 10.1016/j.ica.2023.121518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/08/2023]
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14
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Midgett CR, Kull FJ. Structural Insights into Regulation of Vibrio Virulence Gene Networks. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1404:269-294. [PMID: 36792881 DOI: 10.1007/978-3-031-22997-8_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
One of the best studied aspects of pathogenic Vibrios are the virulence cascades that lead to the production of virulence factors and, ultimately, clinical outcomes. In this chapter, we will examine the regulation of Vibrio virulence gene networks from a structural and biochemical perspective. We will discuss the recent research into the numerous proteins that contribute to regulating virulence in Vibrio spp such as quorum sensing regulator HapR, the transcription factors AphA and AphB, or the virulence regulators ToxR and ToxT. We highlight how insights gained from these studies are already illuminating the basic molecular mechanisms by which the virulence cascade of pathogenic Vibrios unfold and contend that understanding how protein interactions contribute to the host-pathogen communications will enable the development of new antivirulence compounds that can effectively target these pathogens.
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Affiliation(s)
| | - F Jon Kull
- Chemistry Department, Dartmouth College, Hanover, NH, USA.
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15
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Fitzgerald D, Stringer A, Smith C, Lapierre P, Wade JT. Genome-wide mapping of the Escherichia coli PhoB regulon reveals many transcriptionally inert, intragenic binding sites. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.07.527549. [PMID: 36798257 PMCID: PMC9934606 DOI: 10.1101/2023.02.07.527549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
Genome-scale analyses have revealed many transcription factor binding sites within, rather than upstream of genes, raising questions as to the function of these binding sites. Here, we use complementary approaches to map the regulon of the Escherichia coli transcription factor PhoB, a response regulator that controls transcription of genes involved in phosphate homeostasis. Strikingly, the majority of PhoB binding sites are located within genes, but these intragenic sites are not associated with detectable transcription regulation and are not evolutionarily conserved. Many intragenic PhoB sites are located in regions bound by H-NS, likely due to shared sequence preferences of PhoB and H-NS. However, these PhoB binding sites are not associated with transcription regulation even in the absence of H-NS. We propose that for many transcription factors, including PhoB, binding sites not associated with promoter sequences are transcriptionally inert, and hence are tolerated as genomic "noise". IMPORTANCE Recent studies have revealed large numbers of transcription factor binding sites within the genes of bacteria. The function, if any, of the vast majority of these binding sites has not been investigated. Here, we map the binding of the transcription factor PhoB across the Escherichia coli genome, revealing that the majority of PhoB binding sites are within genes. We show that PhoB binding sites within genes are not associated with regulation of the overlapping genes. Indeed, our data suggest that bacteria tolerate the presence of large numbers of non-regulatory, intragenic binding sites for transcription factors, and that these binding sites are not under selective pressure.
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Affiliation(s)
- Devon Fitzgerald
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
- Department of Biomedical Sciences, School of Public Health, University at Albany, Albany, New York, USA
| | - Anne Stringer
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - Carol Smith
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - Pascal Lapierre
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - Joseph T. Wade
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
- Department of Biomedical Sciences, School of Public Health, University at Albany, Albany, New York, USA
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16
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A Copper-Responsive Two-Component System Governs Lipoprotein Remodeling in Listeria monocytogenes. J Bacteriol 2023; 205:e0039022. [PMID: 36622228 PMCID: PMC9879112 DOI: 10.1128/jb.00390-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Bacterial lipoproteins are membrane-associated proteins with a characteristic acylated N-terminal cysteine residue anchoring C-terminal globular domains to the membrane surface. While all lipoproteins are modified with acyl chains, the number, length, and position can vary depending on host. The acylation pattern also alters ligand recognition by the Toll-like receptor 2 (TLR2) protein family, a signaling system that is central to bacterial surveillance and innate immunity. In select Listeria monocytogenes isolates carrying certain plasmids, copper exposure converts the lipoprotein chemotype into a weak TLR2 ligand through expression of the enzyme lipoprotein intramolecular acyltransferase (Lit). In this study, we identify the response regulator (CopR) from a heavy metal-sensing two-component system as the transcription factor that integrates external copper levels with lipoprotein structural modifications. We show that phosphorylated CopR controls the expression of three distinct transcripts within the plasmid cassette encoding Lit2, prolipoprotein diacylglyceryl transferase (Lgt2), putative copper resistance determinants, and itself (the CopRS two-component system). CopR recognizes a direct repeat half-site consensus motif (TCTACACA) separated by 3 bp that overlaps the -35 promoter element. Target gene expression and lipoprotein conversion were not observed in the absence of the response regulator, indicating that CopR phosphorylation is the dominant mechanism of regulation. IMPORTANCE Copper is a frontline antimicrobial used to limit bacterial growth in multiple settings. Here, we demonstrate how the response regulator CopR from a plasmid-borne two-component system in the opportunistic pathogen L. monocytogenes directly induces lipoprotein remodeling in tandem with copper resistance genes due to extracellular copper stress. Activation of CopR by phosphorylation converts the lipoprotein chemotype from a high- to low-immunostimulatory TLR2 ligand. The two-component system-mediated coregulation of copper resistance determinants, in tandem with lipoprotein biosynthesis demonstrated here in L. monocytogenes, may be a common feature of transmissible copper resistance cassettes found in other Firmicutes.
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17
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Espinosa R, Sørensen MA, Svenningsen SL. Escherichia coli protein synthesis is limited by mRNA availability rather than ribosomal capacity during phosphate starvation. Front Microbiol 2022; 13:989818. [PMID: 36620012 PMCID: PMC9814008 DOI: 10.3389/fmicb.2022.989818] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 11/30/2022] [Indexed: 12/24/2022] Open
Abstract
Protein synthesis is the most energetically costly process in the cell. Consequently, it is a tightly regulated process, and regulation of the resources allocated to the protein synthesis machinery is at the heart of bacterial growth optimization theory. However, the molecular mechanisms that result in dynamic downregulation of protein synthesis in response to nutrient starvation are not well described. Here, we first quantify the Escherichia coli response to phosphate starvation at the level of accumulation rates for protein, RNA and DNA. Escherichia coli maintains a low level of protein synthesis for hours after the removal of phosphate while the RNA contents decrease, primarily as a consequence of ribosomal RNA degradation combined with a reduced RNA synthesis rate. To understand the molecular basis for the low protein synthesis rate of phosphate-starved cells, template mRNA for translation was overproduced in the form of a highly induced long-lived mRNA. Remarkably, starved cells increased the rate of protein synthesis and reduced the rate of ribosomal RNA degradation upon mRNA induction. These observations suggest that protein synthesis in phosphate-starved cells is primarily limited by the availability of template, and does not operate at the maximum capacity of the ribosomes. We suggest that mRNA limitation is an adaptive response to phosphate starvation that prevents the deleterious consequences of overcommitting resources to protein synthesis. Moreover, our results support the model that degradation of ribosomal RNA occurs as a consequence of the availability of idle ribosomal subunits.
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18
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Timofeeva A, Galyamova M, Sedykh S. Prospects for Using Phosphate-Solubilizing Microorganisms as Natural Fertilizers in Agriculture. PLANTS 2022; 11:plants11162119. [PMID: 36015422 PMCID: PMC9414882 DOI: 10.3390/plants11162119] [Citation(s) in RCA: 46] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 08/09/2022] [Accepted: 08/11/2022] [Indexed: 11/16/2022]
Abstract
Phosphates are known to be essential for plant growth and development, with phosphorus compounds being involved in various physiological and biochemical reactions. Phosphates are known as one of the most important factors limiting crop yields. The problem of phosphorus deficiency in the soil has traditionally been solved by applying phosphate fertilizers. However, chemical phosphate fertilizers are considered ineffective compared to the organic fertilizers manure and compost. Therefore, increasing the bioavailability of phosphates for plants is one of the primary goals of sustainable agriculture. Phosphate-solubilizing soil microorganisms can make soil-insoluble phosphate bioavailable for plants through solubilization and mineralization. These microorganisms are currently in the focus of interest due to their advantages, such as environmental friendliness, low cost, and high biological efficiency. In this regard, the solubilization of phosphates by soil microorganisms holds strong potential in research, and inoculation of soils or crops with phosphate-solubilizing bacteria is a promising strategy to improve plant phosphate uptake. In this review, we analyze all the species of phosphate-solubilizing bacteria described in the literature to date. We discuss key mechanisms of solubilization of mineral phosphates and mineralization of organic phosphate-containing compounds: organic acids secreted by bacteria for the mobilization of insoluble inorganic phosphates, and the enzymes hydrolyzing phosphorus-containing organic compounds. We demonstrate that phosphate-solubilizing microorganisms have enormous potency as biofertilizers since they increase phosphorus bioavailability for the plant, promote sustainable agriculture, improve soil fertility, and raise crop yields. The use of phosphate-solubilizing microbes is regarded as a new frontier in increasing plant productivity.
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Affiliation(s)
- Anna Timofeeva
- SB RAS Institute of Chemical Biology and Fundamental Medicine, 630090 Novosibirsk, Russia
| | - Maria Galyamova
- Faculty of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Sergey Sedykh
- SB RAS Institute of Chemical Biology and Fundamental Medicine, 630090 Novosibirsk, Russia
- Faculty of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russia
- Correspondence: ; Tel.: +7-91-3727-1000
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19
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Kong L, Su M, Sang J, Huang S, Wang M, Cai Y, Xie M, Wu J, Wang S, Foster SJ, Zhang J, Han A. The W-Acidic Motif of Histidine Kinase WalK Is Required for Signaling and Transcriptional Regulation in Streptococcus mutans. Front Microbiol 2022; 13:820089. [PMID: 35558126 PMCID: PMC9087282 DOI: 10.3389/fmicb.2022.820089] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 02/14/2022] [Indexed: 02/05/2023] Open
Abstract
In Streptococcus mutans, we find that the histidine kinase WalK possesses the longest C-terminal tail (CTT) among all 14 TCSs, and this tail plays a key role in the interaction of WalK with its response regulator WalR. We demonstrate that the intrinsically disordered CTT is characterized by a conserved tryptophan residue surrounded by acidic amino acids. Mutation in the tryptophan not only disrupts the stable interaction, but also impairs the efficient phosphotransferase and phosphatase activities of WalRK. In addition, the tryptophan is important for WalK to compete with DNA containing a WalR binding motif for the WalR interaction. We further show that the tryptophan is important for in vivo transcriptional regulation and bacterial biofilm formation by S. mutans. Moreover, Staphylococcus aureus WalK also has a characteristic CTT, albeit relatively shorter, with a conserved W-acidic motif, that is required for the WalRK interaction in vitro. Together, these data reveal that the W-acidic motif of WalK is indispensable for its interaction with WalR, thereby playing a key role in the WalRK-dependent signal transduction, transcriptional regulation and biofilm formation.
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Affiliation(s)
- Lingyuan Kong
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, China
| | - Mingyang Su
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, China
| | - Jiayan Sang
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, China
| | - Shanshan Huang
- Department of Clinical Laboratory, The First Affiliated Hospital of Xiamen University, Xiamen, China
| | - Min Wang
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, China
| | - Yongfei Cai
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, China
| | - Mingquan Xie
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, China
| | - Jun Wu
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, China
| | - Shida Wang
- State Key Laboratory for Oral Diseases and National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Simon J Foster
- Department of Molecular Biology and Biotechnology, The Florey Institute, The University of Sheffield, Sheffield, United Kingdom
| | - Jiaqin Zhang
- Department of Clinical Laboratory, The First Affiliated Hospital of Xiamen University, Xiamen, China
| | - Aidong Han
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, China
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20
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Horstmann N, Myers KS, Tran CN, Flores AR, Shelburne III SA. CovS inactivation reduces CovR promoter binding at diverse virulence factor encoding genes in group A Streptococcus. PLoS Pathog 2022; 18:e1010341. [PMID: 35180278 PMCID: PMC8893699 DOI: 10.1371/journal.ppat.1010341] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 03/03/2022] [Accepted: 02/04/2022] [Indexed: 11/18/2022] Open
Abstract
The control of virulence gene regulator (CovR), also called caspsule synthesis regulator (CsrR), is critical to how the major human pathogen group A Streptococcus fine-tunes virulence factor production. CovR phosphorylation (CovR~P) levels are determined by its cognate sensor kinase CovS, and functional abrogating mutations in CovS can occur in invasive GAS isolates leading to hypervirulence. Presently, the mechanism of CovR-DNA binding specificity is unclear, and the impact of CovS inactivation on global CovR binding has not been assessed. Thus, we performed CovR chromatin immunoprecipitation sequencing (ChIP-seq) analysis in the emm1 strain MGAS2221 and its CovS kinase deficient derivative strain 2221-CovS-E281A. We identified that CovR bound in the promoter regions of nearly all virulence factor encoding genes in the CovR regulon. Additionally, direct CovR binding was observed for numerous genes encoding proteins involved in amino acid metabolism, but we found limited direct CovR binding to genes encoding other transcriptional regulators. The consensus sequence AATRANAAAARVABTAAA was present in the promoters of genes directly regulated by CovR, and mutations of highly conserved positions within this motif relieved CovR repression of the hasA and MGAS2221_0187 promoters. Analysis of strain 2221-CovS-E281A revealed that binding of CovR at repressed, but not activated, promoters is highly dependent on CovR~P state. CovR repressed virulence factor encoding genes could be grouped dependent on how CovR~P dependent variation in DNA binding correlated with gene transcript levels. Taken together, the data show that CovR repression of virulence factor encoding genes is primarily direct in nature, involves binding to a newly-identified DNA binding motif, and is relieved by CovS inactivation. These data provide new mechanistic insights into one of the most important bacterial virulence regulators and allow for subsequent focused investigations into how CovR-DNA interaction at directly controlled promoters impacts GAS pathogenesis. Tight regulation of virulence factor production is a critical, but poorly understood aspect of bacterial pathogenesis. The OmpR/PhoB family member control of virulence regulator (CovR) is the master virulence factor controller in group A Streptococcus (GAS), a bacterium which commonly causes a diverse array of human infections. Mutations in the cognate kinase of CovR, CovS, are commonly observed among invasive GAS isolates, but the functional impact of CovS on global CovR function is unknown. Herein, we defined CovR global DNA binding locations, identified a consensus CovR binding motif, and determined how inactivation of the CovR cognate sensor kinase, CovS, impacts CovR-DNA interaction. Our findings show that CovR-repressed virulence factor encoding genes are directly regulated by CovR and that CovS inactivation markedly reduces CovR binding at CovR-repressed promoters. Given the widespread nature of CovR homologues in streptococci and other Gram-positive pathogens, these findings extend understanding of mechanisms by which OmpR/PhoB family members impact the ability of bacteria to cause serious infections.
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Affiliation(s)
- Nicola Horstmann
- Department of Infectious Diseases, Infection Control and Employee Health, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America
| | - Kevin S. Myers
- Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Chau Nguyen Tran
- Department of Infectious Diseases, Infection Control and Employee Health, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America
| | - Anthony R. Flores
- Center for Antimicrobial Resistance and Microbial Genomics McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas, United States of America
- Department of Pediatrics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas, United States of America
| | - Samuel A. Shelburne III
- Department of Infectious Diseases, Infection Control and Employee Health, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America
- * E-mail:
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21
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Park Y, Solhtalab M, Thongsomboon W, Aristilde L. Strategies of organic phosphorus recycling by soil bacteria: acquisition, metabolism, and regulation. ENVIRONMENTAL MICROBIOLOGY REPORTS 2022; 14:3-24. [PMID: 35001516 PMCID: PMC9306846 DOI: 10.1111/1758-2229.13040] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 12/07/2021] [Accepted: 12/14/2021] [Indexed: 05/12/2023]
Abstract
Critical to meeting cellular phosphorus (P) demand, soil bacteria deploy a number of strategies to overcome limitation in inorganic P (Pi ) in soils. As a significant contributor to P recycling, soil bacteria secrete extracellular enzymes to degrade organic P (Po ) in soils into the readily bioavailable Pi . In addition, several Po compounds can be transported directly via specific transporters and subsequently enter intracellular metabolic pathways. In this review, we highlight the strategies that soil bacteria employ to recycle Po from the soil environment. We discuss the diversity of extracellular phosphatases in soils, the selectivity of these enzymes towards various Po biomolecules and the influence of the soil environmental conditions on the enzyme's activities. Moreover, we outline the intracellular metabolic pathways for Po biosynthesis and transporter-assisted Po and Pi uptake at different Pi availabilities. We further highlight the regulatory mechanisms that govern the production of phosphatases, the expression of Po transporters and the key metabolic changes in P metabolism in response to environmental Pi availability. Due to the depletion of natural resources for Pi , we propose future studies needed to leverage bacteria-mediated P recycling from the large pools of Po in soils or organic wastes to benefit agricultural productivity.
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Affiliation(s)
- Yeonsoo Park
- Department of Civil and Environmental Engineering, McCormick School of Engineering and Applied ScienceNorthwestern UniversityEvanstonIL60208USA
- Department of Biological and Environmental EngineeringCornell University, Riley‐Robb HallIthacaNY14853USA
| | - Mina Solhtalab
- Department of Civil and Environmental Engineering, McCormick School of Engineering and Applied ScienceNorthwestern UniversityEvanstonIL60208USA
- Department of Biological and Environmental EngineeringCornell University, Riley‐Robb HallIthacaNY14853USA
| | - Wiriya Thongsomboon
- Department of Civil and Environmental Engineering, McCormick School of Engineering and Applied ScienceNorthwestern UniversityEvanstonIL60208USA
- Department of Chemistry, Faculty of ScienceMahasarakham UniversityMahasarakham44150Thailand
| | - Ludmilla Aristilde
- Department of Civil and Environmental Engineering, McCormick School of Engineering and Applied ScienceNorthwestern UniversityEvanstonIL60208USA
- Department of Biological and Environmental EngineeringCornell University, Riley‐Robb HallIthacaNY14853USA
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22
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Distinct Interaction Mechanism of RNAP and ResD and Distal Subsites for Transcription Activation of Nitrite Reductase in Bacillus subtilisψ. J Bacteriol 2021; 204:e0043221. [PMID: 34898263 DOI: 10.1128/jb.00432-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The ResD-ResE signal transduction system plays a pivotal role in anaerobic nitrate respiration in Bacillus subtilis. The nasD operon encoding nitrite reductase is essential for nitrate respiration and is tightly controlled by the ResD response regulator. To understand the mechanism of ResD-dependent transcription activation of the nasD operon, we explored ResD-RNA polymerase (RNAP), ResD-DNA, and RNAP-DNA interactions required for nasD transcription. Full transcriptional activation requires the upstream promoter region where five molecules of ResD bind. The distal ResD-binding subsite at -87 to -84 partially overlaps a sequence similar to the consensus distal subsite of the upstream (UP) element with which the Escherichia coli C-terminal domain of the α subunit (αCTD) of RNAP interacts to stimulate transcription. We propose that interaction between αCTD and ResD at the promoter-distal site is essential for stimulating nasD transcription. Although nasD has an extended -10 promoter, it lacks a reasonable -35 element. Genetic analysis and structural simulations predicted that the absence of the -35 element might be compensated by interactions between σA and αCTD, and between αCTD and ResD at the promoter-proximal ResD-binding subsite. Thus, our work suggested that ResD likely participates in nasD transcription activation by binding to two αCTD subunits at the proximal and distal promoter sites, representing a unique configuration for transcription activation. IMPORTANCE A significant number of ResD-controlled genes have been identified and transcription regulatory pathways in which ResD participates have emerged. Nevertheless, the mechanism of how ResD activates transcription of different genes in a nucleotide sequence-specific manner has been less explored. This study suggested that among the five ResD-binding subsites in the promoter of the nasD operon, the promoter-proximal and -distal ResD-binding subsites play important roles in nasD activation by adapting different modes of protein-protein and protein-DNA interactions. The finding of a new-type of protein-promoter architecture provides insight into the understanding of transcription activation mechanisms controlled by transcription factors including the ubiquitous response regulators of two-component regulatory systems particularly in Gram-positive bacteria.
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23
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Boshaala A, Said MA, Assirey EA, Alborki ZS, AlObaid AA, Zarrouk A, Warad I. Crystal structure, MEP/DFT/XRD, thione ⇔ thiol tautomerization, thermal, docking, and optical/TD-DFT studies of (E)-methyl 2-(1-phenylethylidene)-hydrazinecarbodithioate ligand. J Mol Struct 2021. [DOI: 10.1016/j.molstruc.2021.130461] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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24
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Maciunas LJ, Porter N, Lee PJ, Gupta K, Loll PJ. Structures of full-length VanR from Streptomyces coelicolor in both the inactive and activated states. Acta Crystallogr D Struct Biol 2021; 77:1027-1039. [PMID: 34342276 PMCID: PMC8329863 DOI: 10.1107/s2059798321006288] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 06/17/2021] [Indexed: 11/10/2022] Open
Abstract
Vancomycin has historically been used as a last-resort treatment for serious bacterial infections. However, vancomycin resistance has become widespread in certain pathogens, presenting a serious threat to public health. Resistance to vancomycin is conferred by a suite of resistance genes, the expression of which is controlled by the VanR-VanS two-component system. VanR is the response regulator in this system; in the presence of vancomycin, VanR accepts a phosphoryl group from VanS, thereby activating VanR as a transcription factor and inducing expression of the resistance genes. This paper presents the X-ray crystal structures of full-length VanR from Streptomyces coelicolor in both the inactive and activated states at resolutions of 2.3 and 2.0 Å, respectively. Comparison of the two structures illustrates that phosphorylation of VanR is accompanied by a disorder-to-order transition of helix 4, which lies within the receiver domain of the protein. This transition generates an interface that promotes dimerization of the receiver domain; dimerization in solution was verified using analytical ultracentrifugation. The inactive conformation of the protein does not appear intrinsically unable to bind DNA; rather, it is proposed that in the activated form DNA binding is enhanced by an avidity effect contributed by the receiver-domain dimerization.
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Affiliation(s)
- Lina J. Maciunas
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA 19102, USA
- Graduate Program in Biochemistry, Drexel University College of Medicine, Philadelphia, PA 19102, USA
| | - Nadia Porter
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA 19102, USA
- Summer Undergraduate Research Fellowship Program, Drexel University College of Medicine, Philadelphia, PA 19102, USA
| | - Paula J. Lee
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA 19102, USA
| | - Kushol Gupta
- Department of Biochemistry and Biophysics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Patrick J. Loll
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA 19102, USA
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25
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Zannoni A, Pelliciari S, Musiani F, Chiappori F, Roncarati D, Scarlato V. Definition of the Binding Architecture to a Target Promoter of HP1043, the Essential Master Regulator of Helicobacter pylori. Int J Mol Sci 2021; 22:ijms22157848. [PMID: 34360614 PMCID: PMC8345958 DOI: 10.3390/ijms22157848] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Revised: 07/13/2021] [Accepted: 07/14/2021] [Indexed: 11/30/2022] Open
Abstract
HP1043 is an essential orphan response regulator of Helicobacter pylori orchestrating multiple crucial cellular processes. Classified as a member of the OmpR/PhoB family of two-component systems, HP1043 exhibits a highly degenerate receiver domain and evolved to function independently of phosphorylation. Here, we investigated the HP1043 binding mode to a target sequence in the hp1227 promoter (Php1227). Scanning mutagenesis of HP1043 DNA-binding domain and consensus sequence led to the identification of residues relevant for the interaction of the protein with a target DNA. These determinants were used as restraints to guide a data-driven protein-DNA docking. Results suggested that, differently from most other response regulators of the same family, HP1043 binds in a head-to-head conformation to the Php1227 target promoter. HP1043 interacts with DNA largely through charged residues and contacts with both major and minor grooves of the DNA are required for a stable binding. Computational alanine scanning on molecular dynamics trajectory was performed to corroborate our findings. Additionally, in vitro transcription assays confirmed that HP1043 positively stimulates the activity of RNA polymerase.
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Affiliation(s)
- Annamaria Zannoni
- Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, 40126 Bologna, Italy; (A.Z.); (S.P.); (F.M.)
| | - Simone Pelliciari
- Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, 40126 Bologna, Italy; (A.Z.); (S.P.); (F.M.)
| | - Francesco Musiani
- Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, 40126 Bologna, Italy; (A.Z.); (S.P.); (F.M.)
| | - Federica Chiappori
- Istituto di Tecnologie Biomediche-Consiglio Nazionale delle Ricerche (ITB-CNR), 20054 Segrate, Italy;
| | - Davide Roncarati
- Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, 40126 Bologna, Italy; (A.Z.); (S.P.); (F.M.)
- Correspondence: (D.R.); (V.S.)
| | - Vincenzo Scarlato
- Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, 40126 Bologna, Italy; (A.Z.); (S.P.); (F.M.)
- Correspondence: (D.R.); (V.S.)
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26
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Park SS, Lee S, Rhee DK. Crystal Structure of the Pneumococcal Vancomycin-Resistance Response Regulator DNA-Binding Domain. Mol Cells 2021; 44:179-185. [PMID: 33795535 PMCID: PMC8019601 DOI: 10.14348/molcells.2021.2235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 02/10/2021] [Accepted: 02/25/2021] [Indexed: 11/27/2022] Open
Abstract
Vancomycin response regulator (VncR) is a pneumococcal response regulator of the VncRS two-component signal transduction system (TCS) of Streptococcus pneumoniae. VncRS regulates bacterial autolysis and vancomycin resistance. VncR contains two different functional domains, the N-terminal receiver domain and C-terminal effector domain. Here, we investigated VncR C-terminal DNA binding domain (VncRc) structure using a crystallization approach. Crystallization was performed using the micro-batch method. The crystals diffracted to a 1.964 Å resolution and belonged to space group P212121. The crystal unit-cell parameters were a = 25.71 Å, b = 52.97 Å, and c = 60.61 Å. The structure of VncRc had a helix-turn-helix motif highly similar to the response regulator PhoB of Escherichia coli. In isothermal titration calorimetry and size exclusion chromatography results, VncR formed a complex with VncS, a sensor histidine kinase of pneumococcal TCS. Determination of VncR structure will provide insight into the mechanism by how VncR binds to target genes.
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Affiliation(s)
- Sang-Sang Park
- School of Pharmacy, Sungkyunkwan University, Suwon 16419, Korea
| | - Sangho Lee
- Department of Biological Sciences, Sungkyunkwan University, Suwon 16419, Korea
| | - Dong-Kwon Rhee
- School of Pharmacy, Sungkyunkwan University, Suwon 16419, Korea
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27
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de Pina LC, da Silva FSH, Galvão TC, Pauer H, Ferreira RBR, Antunes LCM. The role of two-component regulatory systems in environmental sensing and virulence in Salmonella. Crit Rev Microbiol 2021; 47:397-434. [PMID: 33751923 DOI: 10.1080/1040841x.2021.1895067] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Adaptation to environments with constant fluctuations imposes challenges that are only overcome with sophisticated strategies that allow bacteria to perceive environmental conditions and develop an appropriate response. The gastrointestinal environment is a complex ecosystem that is home to trillions of microorganisms. Termed microbiota, this microbial ensemble plays important roles in host health and provides colonization resistance against pathogens, although pathogens have evolved strategies to circumvent this barrier. Among the strategies used by bacteria to monitor their environment, one of the most important are the sensing and signalling machineries of two-component systems (TCSs), which play relevant roles in the behaviour of all bacteria. Salmonella enterica is no exception, and here we present our current understanding of how this important human pathogen uses TCSs as an integral part of its lifestyle. We describe important aspects of these systems, such as the stimuli and responses involved, the processes regulated, and their roles in virulence. We also dissect the genomic organization of histidine kinases and response regulators, as well as the input and output domains for each TCS. Lastly, we explore how these systems may be promising targets for the development of antivirulence therapeutics to combat antibiotic-resistant infections.
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Affiliation(s)
- Lucindo Cardoso de Pina
- Escola Nacional de Saúde Pública Sergio Arouca, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.,Programa de Pós-Graduação em Biociências, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil.,Programa de Pós-Graduação Ciência para o Desenvolvimento, Instituto Gulbenkian de Ciência, Oeiras, Portugal
| | | | - Teca Calcagno Galvão
- Laboratório de Genômica Funcional e Bioinformática, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | - Heidi Pauer
- Centro de Desenvolvimento Tecnológico em Saúde, Fundação Oswaldo Cruz, Instituto Nacional de Ciência e Tecnologia de Inovação em Doenças de Populações Negligenciadas, Rio de Janeiro, Brazil
| | | | - L Caetano M Antunes
- Escola Nacional de Saúde Pública Sergio Arouca, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.,Centro de Desenvolvimento Tecnológico em Saúde, Fundação Oswaldo Cruz, Instituto Nacional de Ciência e Tecnologia de Inovação em Doenças de Populações Negligenciadas, Rio de Janeiro, Brazil.,Laboratório de Pesquisa em Infecção Hospitalar, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
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28
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Parise D, Teixeira Dornelles Parise M, Pinto Gomide AC, Figueira Aburjaile F, Bentes Kato R, Salgado-Albarrán M, Tauch A, Ariston de Carvalho Azevedo V, Baumbach J. The Transcriptional Regulatory Network of Corynebacterium pseudotuberculosis. Microorganisms 2021; 9:microorganisms9020415. [PMID: 33671149 PMCID: PMC7923171 DOI: 10.3390/microorganisms9020415] [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] [Received: 02/05/2021] [Revised: 02/11/2021] [Accepted: 02/14/2021] [Indexed: 12/26/2022] Open
Abstract
Corynebacterium pseudotuberculosis is a Gram-positive, facultative intracellular, pathogenic bacterium that infects several different hosts, yielding serious economic losses in livestock farming. It causes several diseases including oedematous skin disease (OSD) in buffaloes, ulcerative lymphangitis (UL) in horses, and caseous lymphadenitis (CLA) in sheep, goats and humans. Despite its economic and medical-veterinary importance, our understanding concerning this organism’s transcriptional regulatory mechanisms is still limited. Here, we review the state of the art knowledge on transcriptional regulatory mechanisms of this pathogenic species, covering regulatory interactions mediated by two-component systems, transcription factors and sigma factors. Key transcriptional regulatory players involved in virulence and pathogenicity of C. pseudotuberculosis, such as the PhoPR system and DtxR, are in the focus of this review, as these regulators are promising targets for future vaccine design and drug development. We conclude that more experimental studies are needed to further understand the regulatory repertoire of this important zoonotic pathogen, and that regulators are promising targets for future vaccine design and drug development.
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Affiliation(s)
- Doglas Parise
- Chair of Experimental Bioinformatics, TUM School of Life Sciences, Technical University of Munich, 85354 Freising-Weihenstephan, Germany; (M.T.D.P.); (M.S.-A.); (J.B.)
- Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil; (A.C.P.G.); (R.B.K.); (V.A.d.C.A.)
- Correspondence: or
| | - Mariana Teixeira Dornelles Parise
- Chair of Experimental Bioinformatics, TUM School of Life Sciences, Technical University of Munich, 85354 Freising-Weihenstephan, Germany; (M.T.D.P.); (M.S.-A.); (J.B.)
- Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil; (A.C.P.G.); (R.B.K.); (V.A.d.C.A.)
| | - Anne Cybelle Pinto Gomide
- Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil; (A.C.P.G.); (R.B.K.); (V.A.d.C.A.)
| | | | - Rodrigo Bentes Kato
- Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil; (A.C.P.G.); (R.B.K.); (V.A.d.C.A.)
| | - Marisol Salgado-Albarrán
- Chair of Experimental Bioinformatics, TUM School of Life Sciences, Technical University of Munich, 85354 Freising-Weihenstephan, Germany; (M.T.D.P.); (M.S.-A.); (J.B.)
- Departamento de Ciencias Naturales, Universidad Autónoma Metropolitana Cuajimalpa, Mexico City 05348, Mexico
| | - Andreas Tauch
- Center for Biotechnology (CeBiTec), Bielefeld University, 33615 Bielefeld, Germany;
| | - Vasco Ariston de Carvalho Azevedo
- Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil; (A.C.P.G.); (R.B.K.); (V.A.d.C.A.)
| | - Jan Baumbach
- Chair of Experimental Bioinformatics, TUM School of Life Sciences, Technical University of Munich, 85354 Freising-Weihenstephan, Germany; (M.T.D.P.); (M.S.-A.); (J.B.)
- Computational BioMedicine lab, Institute of Mathematics and Computer Science, University of Southern Denmark, 5230 Odense, Denmark
- Chair of Computational Systems Biology, University of Hamburg, 22607 Hamburg, Germany
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29
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Pi H, Chu ML, Ivan SJ, Latario CJ, Toth AM, Carlin SM, Hillebrand GH, Lin HK, Reppart JD, Stauff DL, Skaar EP. Directed evolution reveals the mechanism of HitRS signaling transduction in Bacillus anthracis. PLoS Pathog 2020; 16:e1009148. [PMID: 33362282 PMCID: PMC7790381 DOI: 10.1371/journal.ppat.1009148] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Revised: 01/07/2021] [Accepted: 11/11/2020] [Indexed: 12/03/2022] Open
Abstract
Two component systems (TCSs) are a primary mechanism of signal sensing and response in bacteria. Systematic characterization of an entire TCS could provide a mechanistic understanding of these important signal transduction systems. Here, genetic selections were employed to dissect the molecular basis of signal transduction by the HitRS system that detects cell envelope stress in the pathogen Bacillus anthracis. Numerous point mutations were isolated within HitRS, 17 of which were in a 50-residue HAMP domain. Mutational analysis revealed the importance of hydrophobic interactions within the HAMP domain and highlighted its essentiality in TCS signaling. In addition, these data defined residues critical for activities intrinsic to HitRS, uncovered specific interactions among individual domains and between the two signaling proteins, and revealed that phosphotransfer is the rate-limiting step for signal transduction. Furthermore, this study establishes the use of unbiased genetic selections to study TCS signaling and provides a comprehensive mechanistic understanding of an entire TCS. Bacterial TCSs are a primary strategy for stress sensing and niche adaptation. Although individual domains and proteins of these systems have been extensively studied, systematic characterization of an entire TCS is rare. In this study, through unbiased genetic selections and rigorous biochemical analysis, we provide a detailed characterization and structure-function analysis of an entire TCS and extend our understanding of the molecular basis of signal transduction through TCSs. Moreover, this study provides a comprehensive map of point-mutations in these well-conserved signaling proteins, which will be broadly useful for studying other TCSs. The described genetic selection strategies are applicable to any TCS, providing a powerful tool for researchers interested in microbial signal transduction.
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Affiliation(s)
- Hualiang Pi
- Department of Pathology, Microbiology, & Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Vanderbilt Institute for Infection, Immunology, & Inflammation, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Michelle L. Chu
- Department of Biology, Grove City College, Grove City, Pennsylvania, United States of America
| | - Samuel J. Ivan
- Department of Biology, Grove City College, Grove City, Pennsylvania, United States of America
| | - Casey J. Latario
- Department of Biology, Grove City College, Grove City, Pennsylvania, United States of America
| | - Allen M. Toth
- Department of Biology, Grove City College, Grove City, Pennsylvania, United States of America
| | - Sophia M. Carlin
- Department of Biology, Grove City College, Grove City, Pennsylvania, United States of America
| | - Gideon H. Hillebrand
- Department of Biology, Grove City College, Grove City, Pennsylvania, United States of America
| | - Hannah K. Lin
- Department of Biology, Grove City College, Grove City, Pennsylvania, United States of America
| | - Jared D. Reppart
- Department of Biology, Grove City College, Grove City, Pennsylvania, United States of America
| | - Devin L. Stauff
- Department of Biology, Grove City College, Grove City, Pennsylvania, United States of America
| | - Eric P. Skaar
- Department of Pathology, Microbiology, & Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Vanderbilt Institute for Infection, Immunology, & Inflammation, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- * E-mail:
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30
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Structural basis for promoter DNA recognition by the response regulator OmpR. J Struct Biol 2020; 213:107638. [PMID: 33152421 DOI: 10.1016/j.jsb.2020.107638] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 09/29/2020] [Accepted: 10/04/2020] [Indexed: 11/21/2022]
Abstract
OmpR, a response regulator of the EnvZ/OmpR two-component system (TCS), controls the reciprocal regulation of two porin proteins, OmpF and OmpC, in bacteria. During signal transduction, OmpR (OmpR-FL) undergoes phosphorylation at its conserved Asp residue in the N-terminal receiver domain (OmpRn) and recognizes the promoter DNA from its C-terminal DNA-binding domain (OmpRc) to elicit an adaptive response. Apart from that, OmpR regulates many genes in Escherichia coli and is important for virulence in several pathogens. However, the molecular mechanism of the regulation and the structural basis of OmpR-DNA binding is still not fully clear. In this study, we presented the crystal structure of OmpRc in complex with the F1 region of the ompF promoter DNA from E. coli. Our structural analysis suggested that OmpRc binds to its cognate DNA as a homodimer, only in a head-to-tail orientation. Also, the OmpRc apo-form showed a unique domain-swapped crystal structure under different crystallization conditions. Biophysical experimental data, such as NMR, fluorescent polarization and thermal stability, showed that inactive OmpR-FL (unphosphorylated) could bind to promoter DNA with a weaker binding affinity as compared with active OmpR-FL (phosphorylated) or OmpRc, and also confirmed that phosphorylation may only enhance DNA binding. Furthermore, the dimerization interfaces in the OmpRc-DNA complex structure identified in this study provide an opportunity to understand the regulatory role of OmpR and explore the potential for this "druggable" target.
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31
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Shulami S, Zehavi A, Belakhov V, Salama R, Lansky S, Baasov T, Shoham G, Shoham Y. Cross-utilization of β-galactosides and cellobiose in Geobacillus stearothermophilus. J Biol Chem 2020; 295:10766-10780. [PMID: 32493770 DOI: 10.1074/jbc.ra120.014029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 06/02/2020] [Indexed: 11/06/2022] Open
Abstract
Strains of the Gram-positive, thermophilic bacterium Geobacillus stearothermophilus possess elaborate systems for the utilization of hemicellulolytic polysaccharides, including xylan, arabinan, and galactan. These systems have been studied extensively in strains T-1 and T-6, representing microbial models for the utilization of soil polysaccharides, and many of their components have been characterized both biochemically and structurally. Here, we characterized routes by which G. stearothermophilus utilizes mono- and disaccharides such as galactose, cellobiose, lactose, and galactosyl-glycerol. The G. stearothermophilus genome encodes a phosphoenolpyruvate carbohydrate phosphotransferase system (PTS) for cellobiose. We found that the cellobiose-PTS system is induced by cellobiose and characterized the corresponding GH1 6-phospho-β-glucosidase, Cel1A. The bacterium also possesses two transport systems for galactose, a galactose-PTS system and an ABC galactose transporter. The ABC galactose transport system is regulated by a three-component sensing system. We observed that both systems, the sensor and the transporter, utilize galactose-binding proteins that also bind glucose with the same affinity. We hypothesize that this allows the cell to control the flux of galactose into the cell in the presence of glucose. Unexpectedly, we discovered that G. stearothermophilus T-1 can also utilize lactose and galactosyl-glycerol via the cellobiose-PTS system together with a bifunctional 6-phospho-β-gal/glucosidase, Gan1D. Growth curves of strain T-1 growing in the presence of cellobiose, with either lactose or galactosyl-glycerol, revealed initially logarithmic growth on cellobiose and then linear growth supported by the additional sugars. We conclude that Gan1D allows the cell to utilize residual galactose-containing disaccharides, taking advantage of the promiscuity of the cellobiose-PTS system.
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Affiliation(s)
- Smadar Shulami
- Department of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Arie Zehavi
- Department of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Valery Belakhov
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa, Israel
| | - Rachel Salama
- Department of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Shifra Lansky
- Institute of Chemistry and the Laboratory for Structural Chemistry and Biology, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Timor Baasov
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa, Israel
| | - Gil Shoham
- Institute of Chemistry and the Laboratory for Structural Chemistry and Biology, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Yuval Shoham
- Department of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa, Israel
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Miyake Y, Yamamoto K. Epistatic Effect of Regulators to the Adaptive Growth of Escherichia coli. Sci Rep 2020; 10:3661. [PMID: 32108145 PMCID: PMC7046781 DOI: 10.1038/s41598-020-60353-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 02/11/2020] [Indexed: 11/09/2022] Open
Abstract
Bacteria survive in the environment with three steps: a sensing environmental conditions, a responding to sensed signals, and an adaptation for proper survival in the environment. An adapting bacterial cell occurs cell division to increase the number of sister cells, termed adaptive growth. Two-component systems (TCSs), representing the main bacterial signal transduction systems, consist of a pair of one sensor kinase (SK) and one response regulator (RR), and RR genes are abundant in most bacterial genomes as part of the core genome. The OmpR gene family, a group of RR genes, is conserved in 95% of known bacterial genomes. The Escherichia coli genome has an estimated 34 RR genes in total, including 14 genes of OmpR family genes. To reveal the contribution of TCSs for fast growth as an adaptive growth strategy of E. coli, we isolated a set of gene knockout strains by using newly developed genome editing technology, the HoSeI (Homologous Sequence Integration) method, based on CRISPR-Cas9. The statistics of single cell observation show a knockout of an arbitrary pair of phoP, phoB, and ompR genes, stably expressed by positive feedback regulation, dramatically inhibit the optimum adaptive growth of E. coli. These insights suggest that the adaptive growth of bacteria is fulfilled by the optimum high intracellular level of regulators acquired during growth under environmental conditions.
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Affiliation(s)
- Yukari Miyake
- Hosei University, Department of Frontier Bioscience, Koganei, Tokyo, 184-8584, Japan
| | - Kaneyoshi Yamamoto
- Hosei University, Department of Frontier Bioscience, Koganei, Tokyo, 184-8584, Japan.
- Hosei University, Research Institute of Micro-Nano Technology, Koganei, Tokyo, 184-8584, Japan.
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Hochstrasser R, Hutter CAJ, Arnold FM, Bärlocher K, Seeger MA, Hilbi H. The structure of the
Legionella
response regulator LqsR reveals amino acids critical for phosphorylation and dimerization. Mol Microbiol 2020; 113:1070-1084. [DOI: 10.1111/mmi.14477] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 01/20/2020] [Accepted: 01/21/2020] [Indexed: 12/16/2022]
Affiliation(s)
- Ramon Hochstrasser
- Institute of Medical Microbiology University of Zürich Zürich Switzerland
| | | | - Fabian M. Arnold
- Institute of Medical Microbiology University of Zürich Zürich Switzerland
| | - Kevin Bärlocher
- Institute of Medical Microbiology University of Zürich Zürich Switzerland
| | - Markus A. Seeger
- Institute of Medical Microbiology University of Zürich Zürich Switzerland
| | - Hubert Hilbi
- Institute of Medical Microbiology University of Zürich Zürich Switzerland
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Abstract
Phosphorus is required for many biological molecules and essential functions, including DNA replication, transcription of RNA, protein translation, posttranslational modifications, and numerous facets of metabolism. In order to maintain the proper level of phosphate for these processes, many bacteria adapt to changes in environmental phosphate levels. The mechanisms for sensing phosphate levels and adapting to changes have been extensively studied for multiple organisms. The phosphate response of Escherichia coli alters the expression of numerous genes, many of which are involved in the acquisition and scavenging of phosphate more efficiently. This review shares findings on the mechanisms by which E. coli cells sense and respond to changes in environmental inorganic phosphate concentrations by reviewing the genes and proteins that regulate this response. The PhoR/PhoB two-component signal transduction system is central to this process and works in association with the high-affinity phosphate transporter encoded by the pstSCAB genes and the PhoU protein. Multiple models to explain how this process is regulated are discussed.
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35
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Martín JF, Liras P. The Balance Metabolism Safety Net: Integration of Stress Signals by Interacting Transcriptional Factors in Streptomyces and Related Actinobacteria. Front Microbiol 2020; 10:3120. [PMID: 32038560 PMCID: PMC6988585 DOI: 10.3389/fmicb.2019.03120] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 12/24/2019] [Indexed: 12/19/2022] Open
Abstract
Soil dwelling Streptomyces species are faced with large variations in carbon or nitrogen sources, phosphate, oxygen, iron, sulfur, and other nutrients. These drastic changes in key nutrients result in an unbalanced metabolism that have undesirable consequences for growth, cell differentiation, reproduction, and secondary metabolites biosynthesis. In the last decades evidence has accumulated indicating that mechanisms to correct metabolic unbalances in Streptomyces species take place at the transcriptional level, mediated by different transcriptional factors. For example, the master regulator PhoP and the large SARP-type regulator AfsR bind to overlapping sequences in the afsS promoter and, therefore, compete in the integration of signals of phosphate starvation and S-adenosylmethionine (SAM) concentrations. The cross-talk between phosphate control of metabolism, mediated by the PhoR-PhoP system, and the pleiotropic orphan nitrogen regulator GlnR, is very interesting; PhoP represses GlnR and other nitrogen metabolism genes. The mechanisms of control by GlnR of several promoters of ATP binding cassettes (ABC) sugar transporters and carbon metabolism are highly elaborated. Another important cross-talk that governs nitrogen metabolism involves the competition between GlnR and the transcriptional factor MtrA. GlnR and MtrA exert opposite effects on expression of nitrogen metabolism genes. MtrA, under nitrogen rich conditions, represses expression of nitrogen assimilation and regulatory genes, including GlnR, and competes with GlnR for the GlnR binding sites. Strikingly, these sites also bind to PhoP. Novel examples of interacting transcriptional factors, discovered recently, are discussed to provide a broad view of this interactions. Altogether, these findings indicate that cross-talks between the major transcriptional factors protect the cell metabolic balance. A detailed analysis of the transcriptional factors binding sequences suggests that the transcriptional factors interact with specific regions, either by overlapping the recognition sequence of other factors or by binding to adjacent sites in those regions. Additional interactions on the regulatory backbone are provided by sigma factors, highly phosphorylated nucleotides, cyclic dinucleotides, and small ligands that interact with cognate receptor proteins and with TetR-type transcriptional regulators. We propose to define the signal integration DNA regions (so called integrator sites) that assemble responses to different stress, nutritional or environmental signals. These integrator sites constitute nodes recognized by two, three, or more transcriptional factors to compensate the unbalances produced by metabolic stresses. This interplay mechanism acts as a safety net to prevent major damage to the metabolism under extreme nutritional and environmental conditions.
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Affiliation(s)
- Juan F Martín
- Área de Microbiología, Departamento de Biología Molecular, Universidad de León, León, Spain
| | - Paloma Liras
- Área de Microbiología, Departamento de Biología Molecular, Universidad de León, León, Spain
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36
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Kenney LJ, Anand GS. EnvZ/OmpR Two-Component Signaling: An Archetype System That Can Function Noncanonically. EcoSal Plus 2020; 9:10.1128/ecosalplus.ESP-0001-2019. [PMID: 32003321 PMCID: PMC7192543 DOI: 10.1128/ecosalplus.esp-0001-2019] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2019] [Indexed: 01/09/2023]
Abstract
Two-component regulatory systems represent the major paradigm for signal transduction in prokaryotes. The simplest systems are composed of a sensor kinase and a response regulator. The sensor is often a membrane protein that senses a change in environmental conditions and is autophosphorylated by ATP on a histidine residue. The phosphoryl group is transferred onto an aspartate of the response regulator, which activates the regulator and alters its output, usually resulting in a change in gene expression. In this review, we present a historical view of the archetype EnvZ/OmpR two-component signaling system, and then we provide a new view of signaling based on our recent experiments. EnvZ responds to cytoplasmic signals that arise from changes in the extracellular milieu, and OmpR acts canonically (requiring phosphorylation) to regulate the porin genes and noncanonically (without phosphorylation) to activate the acid stress response. Herein, we describe how insights gleaned from stimulus recognition and response in EnvZ are relevant to nearly all sensor kinases and response regulators.
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Affiliation(s)
- Linda J Kenney
- Department of Biochemistry & Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555
- Mechanobiology Institute, T-Lab, National University of Singapore, Singapore
| | - Ganesh S Anand
- Department of Biological Sciences, National University of Singapore, Singapore
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Crosby HA, Tiwari N, Kwiecinski JM, Xu Z, Dykstra A, Jenul C, Fuentes EJ, Horswill AR. The Staphylococcus aureus ArlRS two-component system regulates virulence factor expression through MgrA. Mol Microbiol 2020; 113:103-122. [PMID: 31618469 PMCID: PMC7175635 DOI: 10.1111/mmi.14404] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The Gram-positive bacterium, Staphylococcus aureus, is a versatile pathogen that can sense and adapt to a wide variety of environments within the human host, in part through its 16 two-component regulatory systems. The ArlRS two-component system has been shown to affect many cellular processes in S. aureus, including autolysis, biofilm formation, capsule synthesis and virulence. Yet the molecular details of this regulation remained largely unknown. We used RNA sequencing to identify the ArlRS regulon, and found 70% overlap with that of the global regulator MgrA. These genes included cell wall-anchored adhesins (ebh, sdrD), polysaccharide and capsule synthesis genes, cell wall remodeling genes (lytN, ddh), the urease operon, genes involved in metal transport (feoA, mntH, sirA), anaerobic metabolism genes (adhE, pflA, nrdDG) and a large number of virulence factors (lukSF, lukAB, nuc, gehB, norB, chs, scn and esxA). We show that ArlR directly activates expression of mgrA and identify a probable ArlR-binding site (TTTTCTCAT-N4 -TTTTAATAA). A highly similar sequence is also found in the spx P2 promoter, which was recently shown to be regulated by ArlRS. We also demonstrate that ArlS has kinase activity toward ArlR in vitro, although it has slower kinetics than other similar histidine kinases.
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Affiliation(s)
- Heidi A. Crosby
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO
| | - Nitija Tiwari
- Department of Biochemistry, University of Iowa Carver College of Medicine, Iowa City, IA
| | - Jakub M. Kwiecinski
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO
| | - Zhen Xu
- Department of Biochemistry, University of Iowa Carver College of Medicine, Iowa City, IA
| | - Allison Dykstra
- Department of Biochemistry, University of Iowa Carver College of Medicine, Iowa City, IA
| | - Christian Jenul
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO
| | - Ernesto J Fuentes
- Department of Biochemistry, University of Iowa Carver College of Medicine, Iowa City, IA
| | - Alexander R. Horswill
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO
- Department of Veterans Affairs Eastern Colorado Health Care System, Denver, CO
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38
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New Insights into Multistep-Phosphorelay (MSP)/ Two-Component System (TCS) Regulation: Are Plants and Bacteria that Different? PLANTS 2019; 8:plants8120590. [PMID: 31835810 PMCID: PMC6963811 DOI: 10.3390/plants8120590] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 11/27/2019] [Accepted: 12/07/2019] [Indexed: 12/12/2022]
Abstract
The Arabidopsis multistep-phosphorelay (MSP) is a signaling mechanism based on a phosphorelay that involves three different types of proteins: Histidine kinases, phosphotransfer proteins, and response regulators. Its bacterial equivalent, the two-component system (TCS), is the most predominant device for signal transduction in prokaryotes. The TCS has been extensively studied and is thus generally well-understood. In contrast, the MSP in plants was first described in 1993. Although great advances have been made, MSP is far from being completely comprehended. Focusing on the model organism Arabidopsis thaliana, this review summarized recent studies that have revealed many similarities with bacterial TCSs regarding how TCS/MSP signaling is regulated by protein phosphorylation and dephosphorylation, protein degradation, and dimerization. Thus, comparison with better-understood bacterial systems might be relevant for an improved study of the Arabidopsis MSP.
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39
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Gao R, Stock AM. Overcoming the Cost of Positive Autoregulation by Accelerating the Response with a Coupled Negative Feedback. Cell Rep 2019; 24:3061-3071.e6. [PMID: 30208328 PMCID: PMC6194859 DOI: 10.1016/j.celrep.2018.08.023] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 07/06/2018] [Accepted: 08/08/2018] [Indexed: 12/13/2022] Open
Abstract
A fundamental trade-off between rapid response and optimal expression of genes below cytotoxic levels exists for many signaling circuits, particularly for positively autoregulated systems with an inherent response delay. Here, we describe a regulatory scheme in the E. coli PhoB-PhoR two-component system, which overcomes the cost of positive feedback and achieves both fast and optimal steadystate response for maximal fitness across different environments. Quantitation of the cellular activities enables accurate modeling of the response dynamics to describe how requirements for optimal protein concentrations place limits on response speed. An observed fast response that exceeds the limit led to the prediction and discovery of a coupled negative autoregulation, which allows fast gene expression without increasing steady-state levels. We demonstrate the fitness advantages for the coupled feedbacks in both dynamic and stable environments. Such regulatory schemes offer great flexibility for accurate control of gene expression levels and dynamics upon environmental changes. Positive autoregulation of transcription produces a delayed response. Gao and Stock describe the limit of response delay caused by requirements of optimal protein levels in the PhoBR twocomponent system. Coupled negative autoregulation is discovered to allow a strong promoter for fast response without incurring cost of increasing protein expression levels.
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Affiliation(s)
- Rong Gao
- Center for Advanced Biotechnology and Medicine, Department of Biochemistry and Molecular Biology, Rutgers University-Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA
| | - Ann M Stock
- Center for Advanced Biotechnology and Medicine, Department of Biochemistry and Molecular Biology, Rutgers University-Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA.
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40
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Ghosh P, Shah M, Ravichandran S, Park SS, Iqbal H, Choi S, Kim KK, Rhee DK. Pneumococcal VncR Strain-Specifically Regulates Capsule Polysaccharide Synthesis. Front Microbiol 2019; 10:2279. [PMID: 31632380 PMCID: PMC6781885 DOI: 10.3389/fmicb.2019.02279] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Accepted: 09/18/2019] [Indexed: 11/19/2022] Open
Abstract
Capsular polysaccharides (CPS), a major virulence factor in Streptococcus pneumoniae, become thicker during blood invasion while not during asymptomatic nasopharyngeal colonization. However, the underlying mechanism controlling this differential pneumococcal CPS regulation remain unclear. Here, we show how VncR, the response regulator of the vancomycin resistance locus (vncRS operon), regulates CPS expression in vncR mutants in three serotype (type 2, 3, and 6B) backgrounds upon exposure to serum lactoferrin (LF). Comparative analysis of CPS levels in the wild type (WT) of three strains and their isogenic vncR mutants after LF exposure revealed a strain-specific alteration in CPS production. Consistently, VncR-mediated strain-specific CPS production is correlated with pneumococcal virulence, in vivo. Electrophoretic mobility-shift assay and co-immunoprecipitation revealed an interaction between VncR and the cps promoter (cpsp) in the presence of serum. In addition, in silico analysis uncovered this protein-DNA interaction, suggesting that VncR binds with the cpsp, and recognizes the strain-specific significance of the tandem repeats in cpsp. Taken together, the interaction of VncR and cpsp after serum exposure plays an essential role in regulating differential strain-specific CPS production, which subsequently determines strain-specific systemic virulence. This study highlights how host protein LF contributes to pneumococcal VncR-mediated CPS production. As CPS plays a significant role in immune evasion, these findings suggest that drugs designed to interrupt the VncR-mediated CPS production could help to combat pneumococcal infections.
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Affiliation(s)
| | - Masaud Shah
- Department of Molecular Science and Technology, Ajou University, Suwon, South Korea
| | - Subramaniyam Ravichandran
- Department of Molecular Cell Biology, School of Medicine, Sungkyunkwan University, Suwon, South Korea
| | - Sang-Sang Park
- School of Pharmacy, Sungkyunkwan University, Suwon, South Korea
| | - Hamid Iqbal
- School of Pharmacy, Sungkyunkwan University, Suwon, South Korea
| | - Sangdun Choi
- Department of Molecular Science and Technology, Ajou University, Suwon, South Korea
| | - Kyeong Kyu Kim
- Department of Molecular Cell Biology, School of Medicine, Sungkyunkwan University, Suwon, South Korea
| | - Dong Kwon Rhee
- School of Pharmacy, Sungkyunkwan University, Suwon, South Korea
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41
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Sharma D, Sharma A, Singh B, Verma SK. Bioinformatic Exploration of Metal-Binding Proteome of Zoonotic Pathogen Orientia tsutsugamushi. Front Genet 2019; 10:797. [PMID: 31608099 PMCID: PMC6769048 DOI: 10.3389/fgene.2019.00797] [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: 05/08/2019] [Accepted: 07/30/2019] [Indexed: 12/21/2022] Open
Abstract
Metal ions are involved in many essential biological processes and are crucial for the survival of all organisms. Identification of metal-binding proteins (MBPs) of human affecting pathogens may provide the blueprint for understanding biological metal usage and their putative roles in pathogenesis. This study is focused on the analysis of MBPs from Orientia tsutsugamushi (Ott), a causal agent of scrub typhus in humans. A total of 321 proteins were predicted as putative MBPs, based on sequence search and three-dimensional structure analysis. Majority of proteins could bind with magnesium, and the order of metal binding was Mg > Ca > Zn > Mn > Fe > Cd > Ni > Co > Cu, respectively. The predicted MBPs were functionally classified into nine broad classes. Among them, gene expression and regulation, metabolism, cell signaling, and transport classes were dominant. It was noted that the putative MBPs were localized in all subcellular compartments of Ott, but majorly found in the cytoplasm. Additionally, it was revealed that out of 321 predicted MBPs 245 proteins were putative bacterial toxins and among them, 98 proteins were nonhomologous to human proteome. Sixty putative MBPs showed the ability to interact with drug or drug-like molecules, which indicate that they may be used as broad-spectrum drug targets. These predicted MBPs from Ott could play vital role(s) in various cellular activities and virulence, hence may serve as plausible therapeutic targets to design metal-based drugs to curtail its infection.
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Affiliation(s)
- Dixit Sharma
- Centre for Computational Biology and Bioinformatics, School of Life Sciences, Central University of Himachal Pradesh, Kangra, India
| | - Ankita Sharma
- Centre for Computational Biology and Bioinformatics, School of Life Sciences, Central University of Himachal Pradesh, Kangra, India
| | - Birbal Singh
- ICAR-Indian Veterinary Research Institute, Regional Station, Palampur, India
| | - Shailender Kumar Verma
- Centre for Computational Biology and Bioinformatics, School of Life Sciences, Central University of Himachal Pradesh, Kangra, India
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42
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Yan H, Wang Q, Teng M, Li X. The DNA-binding mechanism of the TCS response regulator ArlR from Staphylococcus aureus. J Struct Biol 2019; 208:107388. [PMID: 31520693 DOI: 10.1016/j.jsb.2019.09.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 09/05/2019] [Accepted: 09/10/2019] [Indexed: 10/26/2022]
Abstract
ArlRS is an essential two-component system in Staphylococcus aureus that regulates the transcription of virulence factors and participate in numerous pathogenic and symbiotic processes. In this work, we identified different DNA binding properties and oligomerization states among the DNA-binding domain of ArlR (ArlRDBD) and the phosphorylated and unphosphorylated full-length ArlR. Based on a 2.5-Å resolution crystal structure of ArlRDBD and subsequent mutagenesis experiments, we confirmed the DNA-binding site of ArlR and the preferred binding sequences in the agr promoter that enables the DNA recognition process. Finally, we propose a putative transcription regulation mechanism for ArlR. This work will facilitate our understanding of the DNA binding affinity regulatory mechanism between the phosphorylated and unphosphorylated response regulator in the two-component system.
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Affiliation(s)
- Hui Yan
- Hefei National Laboratory for Physical Sciences at Microscale, National Synchrotron Radiation Laboratory, School of Life Sciences, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026, China
| | - Qing Wang
- Hefei National Laboratory for Physical Sciences at Microscale, National Synchrotron Radiation Laboratory, School of Life Sciences, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026, China
| | - Maikun Teng
- Hefei National Laboratory for Physical Sciences at Microscale, National Synchrotron Radiation Laboratory, School of Life Sciences, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026, China.
| | - Xu Li
- Hefei National Laboratory for Physical Sciences at Microscale, National Synchrotron Radiation Laboratory, School of Life Sciences, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026, China.
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43
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Morgan SJ, French EL, Plecha SC, Krukonis ES. The wing of the ToxR winged helix-turn-helix domain is required for DNA binding and activation of toxT and ompU. PLoS One 2019; 14:e0221936. [PMID: 31498842 PMCID: PMC6733452 DOI: 10.1371/journal.pone.0221936] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Accepted: 08/19/2019] [Indexed: 02/02/2023] Open
Abstract
ToxR and TcpP, two winged helix-turn-helix (w-HTH) family transcription factors, co-activate expression of the toxT promoter in Vibrio cholerae. ToxT then directly regulates a number of genes required for virulence. In addition to co-activation of toxT, ToxR can directly activate the ompU promoter and repress the ompT promoter. Based on a previous study suggesting that certain wing residues of ToxR are preferentially involved in toxT co-activation compared to direct ompU activation, we employed alanine-scanning mutagenesis to determine which residues in the wing of ToxR are required for activation of each promoter. All of the ToxR wing residues tested that were critical for transcriptional activation of toxT and/or ompU were also critical for DNA binding. While some ToxR wing mutants had reduced interaction with TcpP, that reduced interaction did not correlate with a specific defect in toxT activation. Rather, such mutants also affected ompU activation and DNA binding. Based on these findings we conclude that the primary role of the wing of ToxR is to bind DNA, along with the DNA recognition helix of ToxR, and this function is required both for direct activation of ompU and co-activation of toxT.
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Affiliation(s)
- Sarah J. Morgan
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI, United States of America
| | - Emily L. French
- Division of Integrated Biomedical Sciences, University of Detroit Mercy School of Dentistry, Detroit, MI, United States of America
| | - Sarah C. Plecha
- Division of Integrated Biomedical Sciences, University of Detroit Mercy School of Dentistry, Detroit, MI, United States of America
| | - Eric S. Krukonis
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI, United States of America
- Division of Integrated Biomedical Sciences, University of Detroit Mercy School of Dentistry, Detroit, MI, United States of America
- Department of Biochemistry, Microbiology and Immunology, Wayne State University, Detroit, MI, United States of America
- * E-mail:
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44
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Fernández-Juárez V, Bennasar-Figueras A, Tovar-Sanchez A, Agawin NSR. The Role of Iron in the P-Acquisition Mechanisms of the Unicellular N 2-Fixing Cyanobacteria Halothece sp., Found in Association With the Mediterranean Seagrass Posidonia oceanica. Front Microbiol 2019; 10:1903. [PMID: 31507547 PMCID: PMC6713934 DOI: 10.3389/fmicb.2019.01903] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 08/02/2019] [Indexed: 11/30/2022] Open
Abstract
Posidonia oceanica, an endemic seagrass of the Mediterranean Sea harbors a high diversity of N2-fixing prokaryotes. One of these is Halothece sp., a unicellular N2-fixing cyanobacteria detected through nifH analysis from the epiphytes of P. oceanica. The most related strain in culture is Halothece sp. PCC 7418 and this was used as the test organism in this study. In the Mediterranean Sea, phosphorus (P) and iron (Fe) can be the major limiting nutrients for N2 fixation. However, information about the mechanisms of P-acquisition and the role of metals (i.e., Fe) in these processes for N2-fixing bacteria is scarce. From our genomic analyses of the test organism and other phylogenetically related N2-fixing strains, Halothece sp. PCC 7418 is one of the strains with the greatest number of gene copies (eight copies) of alkaline phosphatases (APases). Our structural analysis of PhoD (alkaline phosphatase type D) and PhoU (phosphate acquisition regulator) of Halothece sp. PCC 7418 showed the connection among metals (Ca2+ and Fe3+), and the P-acquisition mechanisms. Here, we measured the rates of alkaline phosphatase activity (APA) through MUF-P hydrolysis under different combinations of concentrations of inorganic P (PO43−) and Fe in experiments under N2-fixing (low NO3− availability) and non-N2 fixing (high NO3− availability) conditions. Our results showed that APA rates were enhanced by the increase in Fe availability under low levels of PO43−, especially under N2-fixing conditions. Moreover, the increased PO43−-uptake was reflected in the increased of the P-cellular content of the cells under N2 fixation conditions. We also found a positive significant relationship between cellular P and cellular Fe content of the cells (r2 = 0.71, p < 0.05). Our results also indicated that Fe-uptake in Halothece sp. PCC 7418 was P and Fe-dependent. This study gives first insights of P-acquisition mechanisms in the N2-fixing cyanobacteria (Halothece sp.) found in P. oceanica and highlights the role of Fe in these processes.
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Affiliation(s)
- Víctor Fernández-Juárez
- Marine Ecology and Systematics (MarEs), Department of Biology, Universitat de les Illes Balears (UIB), Palma, Spain
| | - Antoni Bennasar-Figueras
- Grup de Recerca en Microbiologia, Departament de Biologia, Universitat de les Illes Balears (UIB), Palma, Spain
| | - Antonio Tovar-Sanchez
- Department of Ecology and Coastal Management, Andalusian Institute for Marine Sciences, ICMAN (CSIC), Cádiz, Spain
| | - Nona Sheila R Agawin
- Marine Ecology and Systematics (MarEs), Department of Biology, Universitat de les Illes Balears (UIB), Palma, Spain
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45
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Regulation of waaH by PhoB during P i Starvation Promotes Biofilm Formation by Escherichia coli O157:H7. J Bacteriol 2019; 201:JB.00093-19. [PMID: 31262835 DOI: 10.1128/jb.00093-19] [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: 01/29/2019] [Accepted: 06/24/2019] [Indexed: 12/30/2022] Open
Abstract
In open environments such as water, enterohemorrhagic Escherichia coli O157:H7 responds to inorganic phosphate (Pi) starvation by inducing the Pho regulon controlled by PhoB. This activates the phosphate-specific transport (Pst) system that contains a high-affinity Pi transporter. In the Δpst mutant, PhoB is constitutively activated and regulates the expression of genes in the Pho regulon. Here, we show that Pi starvation and deletion of the pst system enhance E. coli O157:H7 biofilm formation. Among differentially expressed genes of EDL933 grown under Pi starvation conditions and in the Δpst mutant, we have found that a member of the PhoB regulon, waaH, predicted to encode a glycosyltransferase, was highly expressed. Interestingly, WaaH contributed to biofilm formation of E. coli O157:H7 during both Pi starvation and in the Δpst mutant. In the Δpst mutant, the presence of waaH was associated with lipopolysaccharide (LPS) R3 core type modifications, whereas in E. coli O157:H7, waaH overexpression had no effect on LPS structure during Pi starvation. Therefore, waaH participates in E. coli O157:H7 biofilm formation during Pi starvation, but its biochemical role remains to be clarified. This study highlights the importance of the Pi starvation stress response to biofilm formation, which may contribute to the persistence of E. coli O157:H7 in the environment.IMPORTANCE Enterohemorrhagic Escherichia coli O157:H7 is a human pathogen that causes bloody diarrhea that can result in renal failure. Outside of mammalian hosts, E. coli O157:H7 survives for extended periods of time in nutrient-poor environments, likely as part of biofilms. In E. coli K-12, the levels of free extracellular Pi affect biofilm formation; however, it was unknown whether Pi influences biofilm formation by E. coli O157:H7. Our results show that upon Pi starvation, PhoB activates waaH expression, which favors biofilm formation by E. coli O157:H7. These findings suggest that WaaH is a target for controlling biofilm formation. Altogether, our work demonstrates how adaptation to Pi starvation allows E. coli O157:H7 to occupy different ecological niches.
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Regulatory rewiring through global gene regulations by PhoB and alarmone (p)ppGpp under various stress conditions. Microbiol Res 2019; 227:126309. [PMID: 31421713 DOI: 10.1016/j.micres.2019.126309] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 07/23/2019] [Accepted: 08/02/2019] [Indexed: 12/14/2022]
Abstract
The phosphorus availability in soil ranged from <0.01 to 1 ppm and found limiting for the utilization by plants. Hence, phosphate solubilizing bacteria (PSB) proficiently fulfill the phosphorus requirement of plants in an eco-friendly manner. The PSB encounter dynamic and challenging environmental conditions viz., high temperature, osmotic, acid, and climatic changes often hamper their activity and proficiency. The modern trend is shifting from isolation of the PSB to their genetic potentials and genome annotation not only for their better performance in the field trials but also to study their ability to cope up with stresses. In order to withstand environmental stress, bacteria need to restructure its metabolic network to ensure its survival. Pi starving condition response regulator (PhoB) and the mediator of stringent stress response alarmone (p)ppGpp known to regulate the global regulatory network of bacteria to provide balanced physiology under various stress condition. The current review discusses the global regulation and crosstalk of genes involved in phosphorus homeostasis, solubilization, and various stress response to fine tune the bacterial physiology. The knowledge of these network crosstalk help bacteria to respond efficiently to the challenging environmental parameters, and their physiological plasticity lead us to develop proficient long-lasting consortia for plant growth promotion.
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Azad RN, Zafiropoulos D, Ober D, Jiang Y, Chiu TP, Sagendorf JM, Rohs R, Tullius TD. Experimental maps of DNA structure at nucleotide resolution distinguish intrinsic from protein-induced DNA deformations. Nucleic Acids Res 2019; 46:2636-2647. [PMID: 29390080 PMCID: PMC5946862 DOI: 10.1093/nar/gky033] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 01/15/2018] [Indexed: 12/22/2022] Open
Abstract
Recognition of DNA by proteins depends on DNA sequence and structure. Often unanswered is whether the structure of naked DNA persists in a protein–DNA complex, or whether protein binding changes DNA shape. While X-ray structures of protein–DNA complexes are numerous, the structure of naked cognate DNA is seldom available experimentally. We present here an experimental and computational analysis pipeline that uses hydroxyl radical cleavage to map, at single-nucleotide resolution, DNA minor groove width, a recognition feature widely exploited by proteins. For 11 protein–DNA complexes, we compared experimental maps of naked DNA minor groove width with minor groove width measured from X-ray co-crystal structures. Seven sites had similar minor groove widths as naked DNA and when bound to protein. For four sites, part of the DNA in the complex had the same structure as naked DNA, and part changed structure upon protein binding. We compared the experimental map with minor groove patterns of DNA predicted by two computational approaches, DNAshape and ORChID2, and found good but not perfect concordance with both. This experimental approach will be useful in mapping structures of DNA sequences for which high-resolution structural data are unavailable. This approach allows probing of protein family-dependent readout mechanisms.
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Affiliation(s)
- Robert N Azad
- Department of Chemistry, Boston University, Boston, MA 02215, USA
| | | | - Douglas Ober
- Department of Chemistry, Boston University, Boston, MA 02215, USA
| | - Yining Jiang
- Department of Chemistry, Boston University, Boston, MA 02215, USA
| | - Tsu-Pei Chiu
- Computational Biology and Bioinformatics Program, Departments of Biological Sciences, Chemistry, Physics & Astronomy, and Computer Science, University of Southern California, Los Angeles, CA 90089, USA
| | - Jared M Sagendorf
- Computational Biology and Bioinformatics Program, Departments of Biological Sciences, Chemistry, Physics & Astronomy, and Computer Science, University of Southern California, Los Angeles, CA 90089, USA
| | - Remo Rohs
- Computational Biology and Bioinformatics Program, Departments of Biological Sciences, Chemistry, Physics & Astronomy, and Computer Science, University of Southern California, Los Angeles, CA 90089, USA
| | - Thomas D Tullius
- Department of Chemistry, Boston University, Boston, MA 02215, USA.,Program in Bioinformatics, Boston University, Boston, MA 02215, USA
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Abstract
Response regulators function as the output components of two-component systems, which couple the sensing of environmental stimuli to adaptive responses. Response regulators typically contain conserved receiver (REC) domains that function as phosphorylation-regulated switches to control the activities of effector domains that elicit output responses. This modular design is extremely versatile, enabling different regulatory strategies tuned to the needs of individual signaling systems. This review summarizes structural features that underlie response regulator function. An abundance of atomic resolution structures and complementary biochemical data have defined the mechanisms for response regulator enzymatic activities, revealed trends in regulatory strategies utilized by response regulators of different subfamilies, and provided insights into interactions of response regulators with their cognate histidine kinases. Among the hundreds of thousands of response regulators identified, variations abound. This article provides a framework for understanding structural features that enable function of canonical response regulators and a basis for distinguishing noncanonical configurations.
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Affiliation(s)
- Rong Gao
- Center for Advanced Biotechnology and Medicine, Department of Biochemistry and Molecular Biology, Rutgers-Robert Wood Johnson Medical School, Piscataway, New Jersey 08854, USA; , ,
| | - Sophie Bouillet
- Center for Advanced Biotechnology and Medicine, Department of Biochemistry and Molecular Biology, Rutgers-Robert Wood Johnson Medical School, Piscataway, New Jersey 08854, USA; , ,
| | - Ann M Stock
- Center for Advanced Biotechnology and Medicine, Department of Biochemistry and Molecular Biology, Rutgers-Robert Wood Johnson Medical School, Piscataway, New Jersey 08854, USA; , ,
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Park DM, Taffet MJ. Combinatorial Sensor Design in Caulobacter crescentus for Selective Environmental Uranium Detection. ACS Synth Biol 2019; 8:807-817. [PMID: 30897331 DOI: 10.1021/acssynbio.8b00484] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The ability to detect uranium (U) through environmental monitoring is of critical importance for informing water resource protection and nonproliferation efforts. While technologies exist for environmental U detection, wide-area environmental monitoring, i.e. sampling coverage over large areas not known to possess U contamination, remains a challenging prospect that necessitates the development of novel detection approaches. Herein, we describe the development of a whole-cell U sensor by integrating two functionally independent, native U-responsive two-component signaling systems (TCS), UzcRS and UrpRS, within an AND gate circuit in the bacterium Caulobacter crescentus. Through leverage of the distinct but imperfect selectivity profiles of both TCS, this combinatorial approach enabled greater selectivity relative to a prior biosensor developed with UzcRS alone; no cross-reactivity was observed with most common environmental metals (e.g, Fe, As, Cu, Ca, Mg, Cd, Cr, Al) or the U decay-chain product Th, and the selectivity against Zn and Pb was significantly improved. In addition, integration of the UzcRS signal amplifier protein UzcY within the AND gate circuit further enhanced overall sensitivity and selectivity for U. The functionality of the sensor in an environmental context was confirmed by detection of U concentrations as low as 1 μM in groundwater samples. The results highlight the value of a combinatorial approach for constructing whole-cell sensors for the selective detection of analytes for which there are no known evolved regulators.
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Affiliation(s)
- Dan M. Park
- Biosciences and Biotechnology Division, Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| | - Michael J. Taffet
- Environmental Restoration Department (ERD), Operations and Business Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550, United States
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Dong C, Zhang H, Yang Y, He X, Liu L, Fu J, Shi J, Wu Z. Physiological and transcriptomic analyses to determine the responses to phosphorus utilization in Nostoc sp. HARMFUL ALGAE 2019; 84:10-18. [PMID: 31128794 DOI: 10.1016/j.hal.2019.03.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2018] [Revised: 03/05/2019] [Accepted: 03/08/2019] [Indexed: 05/05/2023]
Abstract
Phosphorus (P) is an important factor driving algal growth in aquatic ecosystems. In the present study, the growth, P uptake and utilization, photosynthesis, and transcriptome profile of Nostoc sp. were measured when Nostoc sp. cultured in media containing β-glycerol phosphate (β-gly, containing COP bonds), 2-aminoethylphosphonic acid (2-amin, containing CP bonds), or orthophosphate (K2HPO4), and in P-free (NP) medium. The results revealed that NP treatment adversely affected the growth and photosynthesis of Nostoc sp. and significantly down-regulated the expression of genes related to nutrient transport and material metabolism. Furthermore, 2-amin treatment reduced the growth of Nostoc sp. but did not significantly reduce photosynthesis, and the treatments of NP and 2-amin up-regulated the expressions of genes related antioxidation and stress. Additionally, there were no obvious differences in growth, photosynthesis, and phosphorus utilization between the β-gly and K2HPO4 treatments. These results suggested that Nostoc had a flexible ability to utilize P, which might play an important role in its widespread distribution in the environment.
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Affiliation(s)
- Congcong Dong
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), Chongqing Key Laboratory of Plant Ecology and Resources Research in Three Gorges Reservoir Region, School of Life Sciences, Southwest University, Chongqing 400715, PR China
| | - Hongbo Zhang
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), Chongqing Key Laboratory of Plant Ecology and Resources Research in Three Gorges Reservoir Region, School of Life Sciences, Southwest University, Chongqing 400715, PR China
| | - Yanjun Yang
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), Chongqing Key Laboratory of Plant Ecology and Resources Research in Three Gorges Reservoir Region, School of Life Sciences, Southwest University, Chongqing 400715, PR China
| | - Xinyu He
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), Chongqing Key Laboratory of Plant Ecology and Resources Research in Three Gorges Reservoir Region, School of Life Sciences, Southwest University, Chongqing 400715, PR China
| | - Li Liu
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), Chongqing Key Laboratory of Plant Ecology and Resources Research in Three Gorges Reservoir Region, School of Life Sciences, Southwest University, Chongqing 400715, PR China
| | - Junke Fu
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), Chongqing Key Laboratory of Plant Ecology and Resources Research in Three Gorges Reservoir Region, School of Life Sciences, Southwest University, Chongqing 400715, PR China
| | - Junqiong Shi
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), Chongqing Key Laboratory of Plant Ecology and Resources Research in Three Gorges Reservoir Region, School of Life Sciences, Southwest University, Chongqing 400715, PR China
| | - Zhongxing Wu
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), Chongqing Key Laboratory of Plant Ecology and Resources Research in Three Gorges Reservoir Region, School of Life Sciences, Southwest University, Chongqing 400715, PR China.
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