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Su HL, Lai SJ, Tsai KC, Fung KM, Lung TL, Hsu HM, Wu YC, Liu CH, Lai HX, Lin JH, Tseng TS. Structure-guided identification and characterization of potent inhibitors targeting PhoP and MtrA to combat mycobacteria. Comput Struct Biotechnol J 2024; 23:1477-1488. [PMID: 38623562 PMCID: PMC11016868 DOI: 10.1016/j.csbj.2024.04.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2023] [Revised: 04/01/2024] [Accepted: 04/01/2024] [Indexed: 04/17/2024] Open
Abstract
Mycobacteria are causative agents of tuberculosis (TB), which is a global health concern. Drug-resistant TB strains are rapidly emerging, thereby necessitating the urgent development of new drugs. Two-component signal transduction systems (TCSs) are signaling pathways involved in the regulation of various bacterial behaviors and responses to environmental stimuli. Applying specific inhibitors of TCSs can disrupt bacterial signaling, growth, and virulence, and can help combat drug-resistant TB. We conducted a comprehensive pharmacophore-based inhibitor screening and biochemical and biophysical examinations to identify, characterize, and validate potential inhibitors targeting the response regulators PhoP and MtrA of mycobacteria. The constructed pharmacophore model Phar-PR-n4 identified effective inhibitors of formation of the PhoP-DNA complex: ST132 (IC50 = 29 ± 1.6 µM) and ST166 (IC50 = 18 ± 1.3 µM). ST166 (KD = 18.4 ± 4.3 μM) and ST132 (KD = 14.5 ± 0.1 μM) strongly targeted PhoP in a slow-on, slow-off manner. The inhibitory potency and binding affinity of ST166 and ST132 for MtrAC were comparable to those of PhoP. Structural analyses and molecular dynamics simulations revealed that ST166 and ST132 mainly interact with the α8-helix and C-terminal β-hairpin of PhoP, with functionally essential residue hotspots for structure-based inhibitor optimization. Moreover, ST166 has in vitro antibacterial activity against Macrobacterium marinum. Thus, ST166, with its characteristic 1,2,5,6-tetrathiocane and terminal sulphonic groups, has excellent potential as a candidate for the development of novel antimicrobial agents to combat pathogenic mycobacteria.
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Affiliation(s)
- Han-Li Su
- Department of Emergency Medicine, Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi City 600, Taiwan
| | - Shu-Jung Lai
- Graduate Institute of Biomedical Sciences, China Medical University, Taichung, Taiwan
- Research Center for Cancer Biology, China Medical University, Taichung, Taiwan
| | - Keng-Chang Tsai
- National Research Institute of Chinese Medicine, Ministry of Health and Welfare, Taipei, Taiwan
- Ph.D. Program in Medical Biotechnology, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
| | - Kit-Man Fung
- Biomedical Translation Research Center (BioTReC), Academia Sinica, Taipei 11529, Taiwan
| | - Tse-Lin Lung
- Institute of Molecular Biology, National Chung Hsing University, Taichung,Taiwan
| | - Hsing-Mien Hsu
- Institute of Molecular Biology, National Chung Hsing University, Taichung,Taiwan
| | - Yi-Chen Wu
- Institute of Molecular Biology, National Chung Hsing University, Taichung,Taiwan
| | - Ching-Hui Liu
- Institute of Molecular Biology, National Chung Hsing University, Taichung,Taiwan
| | - Hui-Xiang Lai
- Institute of Molecular Biology, National Chung Hsing University, Taichung,Taiwan
| | - Jiun-Han Lin
- Department of Industrial Technology, Ministry of Economic Affairs, Taipei, Taiwan
- Food Industry Research and Development Institute, Hsinchu City, Taiwan
| | - Tien-Sheng Tseng
- Institute of Molecular Biology, National Chung Hsing University, Taichung,Taiwan
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Haller YA, Jiang J, Wan Z, Childress A, Wang S, Haydel SE. M. tuberculosis PrrA binds the dosR promoter and regulates mycobacterial adaptation to hypoxia. Tuberculosis (Edinb) 2024; 148:102531. [PMID: 38885567 DOI: 10.1016/j.tube.2024.102531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 05/30/2024] [Accepted: 06/05/2024] [Indexed: 06/20/2024]
Abstract
The PrrAB two-component system (TCS) is essential for Mycobacterium tuberculosis viability. Previously, it was demonstrated that PrrA binds DNA in the absence of PrrB-mediated transphosphorylation and that non-cognate serine/threonine-kinases phosphorylate PrrA threonine-6 (T6). Therefore, we investigated the differential binding affinity and regulatory properties of the M. tuberculosis-derived wild-type PrrA, PrrA phosphomimetic (D58E, T6E), and PrrA phosphoablative (D58A, T6A) proteins with the prrAMtb, dosRMtb, and cydAMtb genes. While we hypothesized greater DNA binding affinity and more pronounced regulation by PrrA phosphomimetic variants, recombinant, wild-type PrrAMtb bound DNA with greatest affinity. Collectively, wild-type PrrAMtb recombinant protein displayed the highest binding affinity to the dosRMtb promoter (KD 3.46 ± 2.09 nM), followed by the prrAMtb promoter (KD 9.00 ± 2.66 nM). To establish PrrAMtb regulatory activity, we constructed M. smegmatis ΔprrABMsmeg::prrAMtb strains with each of the PrrAMtb variants and extrachromosomal prrAMtb, dosRMtb, and cydAMtb promoter-mCherry reporter fusions. Our findings showed that PrrAMtb is autoregulatory and induces dosRMtb expression only during in vitro, hypoxic growth. Combined expression of prrABMtb in M. smegmatis ΔprrAB significantly induced cydAMtb promoter-mCherry expression. Our studies advanced the understanding of PrrA function and PrrAB phosphorylation-mediated regulatory mechanisms and control of mycobacterial dosR and cydA hypoxic and low-oxygen responsive genes.
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Affiliation(s)
- Yannik A Haller
- School of Life Sciences, Arizona State University, Tempe, AZ, USA; Biodesign Institute Center for Bioelectronics and Biosensors, Arizona State University, Tempe, AZ, USA
| | - Jiapei Jiang
- Biodesign Institute Center for Bioelectronics and Biosensors, Arizona State University, Tempe, AZ, USA; School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ, USA
| | - Zijian Wan
- School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ, USA; School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, AZ, USA
| | - Alexia Childress
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
| | - Shaopeng Wang
- Biodesign Institute Center for Bioelectronics and Biosensors, Arizona State University, Tempe, AZ, USA; School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ, USA
| | - Shelley E Haydel
- School of Life Sciences, Arizona State University, Tempe, AZ, USA; Biodesign Institute Center for Bioelectronics and Biosensors, Arizona State University, Tempe, AZ, USA.
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Gao R, Wu T, Stock AM. A conserved inhibitory interdomain interaction regulates DNA-binding activities of hybrid two-component systems in Bacteroides. mBio 2024:e0122024. [PMID: 38842315 DOI: 10.1128/mbio.01220-24] [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: 04/23/2024] [Accepted: 05/02/2024] [Indexed: 06/07/2024] Open
Abstract
Hybrid two-component systems (HTCSs) comprise a major class of transcription regulators of polysaccharide utilization genes in Bacteroides. Distinct from classical two-component systems in which signal transduction is carried out by intermolecular phosphotransfer between a histidine kinase (HK) and a cognate response regulator (RR), HTCSs contain the membrane sensor HK and the RR transcriptional regulator within a single polypeptide chain. Tethering the DNA-binding domain (DBD) of the RR with the dimeric HK domain in an HTCS could potentially promote dimerization of the DBDs and would thus require a mechanism to suppress DNA-binding activity in the absence of stimulus. Analysis of phosphorylation and DNA-binding activities of several HTCSs from Bacteroides thetaiotaomicron revealed a DBD suppression mechanism in which an inhibitory interaction between the DBD and the phosphoryl group-accepting receiver domain (REC) decreases autophosphorylation rates of HTCS-RECs and represses DNA-binding activities in the absence of phosphorylation. Sequence analyses and structure predictions identified a highly conserved sequence motif correlated with a conserved inhibitory domain arrangement of REC and DBD. The presence of the motif, as in most HTCSs, or its absence, in a small subset of HTCSs, is likely predictive of two distinct regulatory mechanisms evolved for different glycans. Substitutions within the conserved motif relieve the inhibitory interaction and result in elevated DNA-binding activities in the absence of phosphorylation. Our data suggest a fundamental regulatory mechanism shared by most HTCSs to suppress DBD activities using a conserved inhibitory interdomain arrangement to overcome the challenge of the fused HK and RR components. IMPORTANCE Different dietary and host-derived complex carbohydrates shape the gut microbial community and impact human health. In Bacteroides, the prevalent gut bacteria genus, utilization of these diverse carbohydrates relies on different gene clusters that are under sophisticated control by various signaling systems, including the hybrid two-component systems (HTCSs). We have uncovered a highly conserved regulatory mechanism in which the output DNA-binding activity of HTCSs is suppressed by interdomain interactions in the absence of stimulating phosphorylation. A consensus amino acid motif is found to correlate with the inhibitory interaction surface while deviations from the consensus can lead to constitutive activation. Understanding of such conserved HTCS features will be important to make regulatory predictions for individual systems as well as to engineer novel systems with substitutions in the consensus to explore the glycan regulation landscape in Bacteroides.
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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, New Jersey, USA
| | - Ti Wu
- Center for Advanced Biotechnology and Medicine, Department of Biochemistry and Molecular Biology, Rutgers University-Robert Wood Johnson Medical School, Piscataway, New Jersey, USA
| | - Ann M Stock
- Center for Advanced Biotechnology and Medicine, Department of Biochemistry and Molecular Biology, Rutgers University-Robert Wood Johnson Medical School, Piscataway, New Jersey, USA
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4
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Shibata M, Lin X, Onuchic JN, Yura K, Cheng RR. Residue coevolution and mutational landscape for OmpR and NarL response regulator subfamilies. Biophys J 2024; 123:681-692. [PMID: 38291753 PMCID: PMC10995415 DOI: 10.1016/j.bpj.2024.01.028] [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: 11/10/2023] [Revised: 12/31/2023] [Accepted: 01/24/2024] [Indexed: 02/01/2024] Open
Abstract
DNA-binding response regulators (DBRRs) are a broad class of proteins that operate in tandem with their partner kinase proteins to form two-component signal transduction systems in bacteria. Typical DBRRs are composed of two domains where the conserved N-terminal domain accepts transduced signals and the evolutionarily diverse C-terminal domain binds to DNA. These domains are assumed to be functionally independent, and hence recombination of the two domains should yield novel DBRRs of arbitrary input/output response, which can be used as biosensors. This idea has been proved to be successful in some cases; yet, the error rate is not trivial. Improvement of the success rate of this technique requires a deeper understanding of the linker-domain and inter-domain residue interactions, which have not yet been thoroughly examined. Here, we studied residue coevolution of DBRRs of the two main subfamilies (OmpR and NarL) using large collections of bacterial amino acid sequences to extensively investigate the evolutionary signatures of linker-domain and inter-domain residue interactions. Coevolutionary analysis uncovered evolutionarily selected linker-domain and inter-domain residue interactions of known experimental structures, as well as previously unknown inter-domain residue interactions. We examined the possibility of these inter-domain residue interactions as contacts that stabilize an inactive conformation of the DBRR where DNA binding is inhibited for both subfamilies. The newly gained insights on linker-domain/inter-domain residue interactions and shared inactivation mechanisms improve the understanding of the functional mechanism of DBRRs, providing clues to efficiently create functional DBRR-based biosensors. Additionally, we show the feasibility of applying coevolutionary landscape models to predict the functionality of domain-swapped DBRR proteins. The presented result demonstrates that sequence information can be used to filter out bioengineered DBRR proteins that are predicted to be nonfunctional due to a high negative predictive value.
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Affiliation(s)
- Mayu Shibata
- Graduate School of Humanities and Sciences, Ochanomizu University, Bunkyo, Tokyo, Japan; Center for Theoretical Biological Physics, Rice University, Houston Texas
| | - Xingcheng Lin
- Department of Physics, North Carolina State University, Raleigh, North Carolina; Bioinformatics Research Center, North Carolina State University, Raleigh, North Carolina
| | - José N Onuchic
- Center for Theoretical Biological Physics, Rice University, Houston Texas; Department of Physics and Astronomy, Chemistry, and Biosciences, Rice University, Houston, Texas
| | - Kei Yura
- Graduate School of Humanities and Sciences, Ochanomizu University, Bunkyo, Tokyo, Japan; Center for Interdisciplinary AI and Data Science, Ochanomizu University, Bunkyo, Tokyo, Japan; Graduate School of Advanced Science and Engineering, Waseda University, Shinjuku, Tokyo, Japan
| | - Ryan R Cheng
- Department of Chemistry, University of Kentucky, Lexington, Kentucky.
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Zhang Z, Yan Y, Pang J, Dai L, Zhang Q, Yu EW. Structural basis of DNA recognition of the Campylobacter jejuni CosR regulator. mBio 2024; 15:e0343023. [PMID: 38323832 PMCID: PMC10936212 DOI: 10.1128/mbio.03430-23] [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: 12/21/2023] [Accepted: 01/09/2024] [Indexed: 02/08/2024] Open
Abstract
Campylobacter jejuni is a foodborne pathogen commonly found in the intestinal tracts of animals. This pathogen is a leading cause of gastroenteritis in humans. Besides its highly infectious nature, C. jejuni is increasingly resistant to a number of clinically administrated antibiotics. As a consequence, the Centers for Disease Control and Prevention has designated antibiotic-resistant Campylobacter as a serious antibiotic resistance threat in the United States. The C. jejuni CosR regulator is essential to the viability of this bacterium and is responsible for regulating the expression of a number of oxidative stress defense enzymes. Importantly, it also modulates the expression of the CmeABC multidrug efflux system, the most predominant and clinically important system in C. jejuni that mediates resistance to multiple antimicrobials. Here, we report structures of apo-CosR and CosR bound with a 21 bp DNA sequence located at the cmeABC promotor region using both single-particle cryo-electron microscopy and X-ray crystallography. These structures allow us to propose a novel mechanism for CosR regulation that involves a long-distance conformational coupling and rearrangement of the secondary structural elements of the regulator to bind target DNA. IMPORTANCE Campylobacter jejuni has emerged as an antibiotic-resistant threat worldwide. CosR is an essential regulator for this bacterium and is important for Campylobacter adaptation to various stresses. Here, we describe the structural basis of CosR binding to target DNA as determined by cryo-electron microscopy and X-ray crystallography. Since CosR is a potential target for intervention, our studies may facilitate the development of novel therapeutics to combat C. jejuni infection.
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Affiliation(s)
- Zhemin Zhang
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
| | - Yuqi Yan
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
| | - Jinji Pang
- Department of Veterinary Microbiology, College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA
| | - Lei Dai
- Department of Veterinary Microbiology, College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA
| | - Qijing Zhang
- Department of Veterinary Microbiology, College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA
| | - Edward W. Yu
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
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6
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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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Structural basis of phosphorylation-induced activation of the response regulator VbrR. Acta Biochim Biophys Sin (Shanghai) 2023; 55:43-50. [PMID: 36647726 PMCID: PMC10157535 DOI: 10.3724/abbs.2022200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
<p indent="0mm">Two-component systems typically consist of a paired histidine kinase and response regulator and couple environmental changes to adaptive responses. The response regulator VbrR from <italic>Vibrio parahaemolyticus</italic>, a member of the OmpR/PhoB family, regulates virulence and antibiotic resistance genes. The activation mechanism of VbrR remains unclear. Here, we report the crystal structures of full-length VbrR in complex with DNA in the active conformation and the N-terminal receiver domain (RD) and the C-terminal DNA-binding domain (DBD) in both active and inactive conformations. Structural and biochemical analyses suggest that unphosphorylated VbrR adopts mainly as inactive dimers through the DBD at the autoinhibitory state. The RD undergoes a monomer-to-dimer transition upon phosphorylation, which further induces the transition of DBD from an autoinhibitory dimer to an active dimer and enables its binding with target DNA. Our study suggests a new model for phosphorylation-induced activation of response regulators and sheds light on the pathogenesis of <italic>V</italic>. <italic>parahaemolyticus</italic>. </p>.
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The Bacterial MtrAB Two-Component System Regulates the Cell Wall Homeostasis Responding to Environmental Alkaline Stress. Microbiol Spectr 2022; 10:e0231122. [PMID: 36073914 PMCID: PMC9602371 DOI: 10.1128/spectrum.02311-22] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Throughout the course of evolution, bacteria have developed signal transduction tools such as two-component systems (TCSs) to meet their demands to thrive even under the most challenging environmental conditions. One TCS called MtrAB is commonly found in Actinobacteria and is implicated in cell wall metabolism, osmoprotection, cell proliferation, antigen secretion, and biosynthesis of secondary metabolites. However, precisely how the MtrAB TCS regulates the bacterial responses to external environments remains unclear. Here, we report that the MtrAB TCS regulates the cell envelope response of alkali-tolerant bacterium Dietzia sp. strain DQ12-45-1b to extreme alkaline stimuli. We found that under alkaline conditions, an mtrAB mutant exhibited both reduced growth and abnormal morphology compared to the wild-type strain. Electrophoretic mobility shift assay analysis showed that MtrA binds the promoter of the mraZ gene critical for cell wall homeostasis, suggesting that MtrA directly controls transcription of this regulator. In conclusion, our findings demonstrate that MtrAB TCS is involved in controlling the bacterial response to alkaline stimuli by regulating the expression of the cell wall homeostasis regulator MraZ in Dietzia sp. DQ12-45-1b, providing novel details critical for a mechanistic understanding of how cell wall homeostasis is controlled. IMPORTANCE Microorganisms can be found in most extreme environments, and they have to adapt to a wide range of environmental stresses. The two-component systems (TCSs) found in bacteria detect environmental stimuli and regulate physiological pathways for survival. The MtrAB TCS conserved in Corynebacterineae is critical for maintaining the metabolism of the cell wall components that protects bacteria from diverse environmental stresses. However, how the MtrAB TCS regulates cell wall homeostasis and adaptation under stress conditions is unclear. Here, we report that the MtrAB TCS in Dietzia sp. DQ12-45-1b plays a critical role in alkaline resistance by modulating the cell wall homeostasis through the MtrAB-MraZ pathway. Thus, our work provides a novel regulatory pathway used by bacteria for adaptation and survival under extreme alkaline stresses.
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9
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Stupar M, Furness J, De Voss CJ, Tan L, West NP. Two-component sensor histidine kinases of Mycobacterium tuberculosis: beacons for niche navigation. Mol Microbiol 2022; 117:973-985. [PMID: 35338720 PMCID: PMC9321153 DOI: 10.1111/mmi.14899] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 03/12/2022] [Accepted: 03/22/2022] [Indexed: 11/27/2022]
Abstract
Intracellular bacterial pathogens such as Mycobacterium tuberculosis are remarkably adept at surviving within a host, employing a variety of mechanisms to counteract host defenses and establish a protected niche. Constant surveying of the environment is key for pathogenic mycobacteria to discern their immediate location and coordinate the expression of genes necessary for adaptation. Two‐component systems efficiently perform this role, typically comprised of a transmembrane sensor kinase and a cytoplasmic response regulator. In this review, we describe the role of two‐component systems in bacterial pathogenesis, focusing predominantly on the role of sensor kinases of M. tuberculosis. We highlight important features of sensor kinases in mycobacterial infection, discuss ways in which these signaling proteins sense and respond to environments, and how this is attuned to their intracellular lifestyle. Finally, we discuss recent studies which have identified and characterized inhibitors of two‐component sensor kinases toward establishing a new strategy in anti‐mycobacterial therapy.
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Affiliation(s)
- Miljan Stupar
- School of Chemistry and Molecular Biosciences, Australian Infectious Disease Research Centre, University of Queensland, Brisbane, 4072, Australia
| | - Juanelle Furness
- School of Chemistry and Molecular Biosciences, Australian Infectious Disease Research Centre, University of Queensland, Brisbane, 4072, Australia
| | - Christopher J De Voss
- School of Chemistry and Molecular Biosciences, Australian Infectious Disease Research Centre, University of Queensland, Brisbane, 4072, Australia
| | - Lendl Tan
- School of Chemistry and Molecular Biosciences, Australian Infectious Disease Research Centre, University of Queensland, Brisbane, 4072, Australia
| | - Nicholas P West
- School of Chemistry and Molecular Biosciences, Australian Infectious Disease Research Centre, University of Queensland, Brisbane, 4072, Australia
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10
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Mutation of MtrA at the Predicted Phosphorylation Site Abrogates Its Role as a Global Regulator in Streptomyces venezuelae. Microbiol Spectr 2022; 10:e0213121. [PMID: 35293797 PMCID: PMC9045223 DOI: 10.1128/spectrum.02131-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The global regulator MtrA controls development and primary and secondary metabolism in Streptomyces species. However, residues critical for its function have not yet been characterized. In this study, we identified residue D53 as the potential phosphorylation site of MtrA from Streptomyces venezuelae, a model Streptomyces strain. MtrA variants with amino acid substitutions at the D53 site were generated, and the effects of these substitutions were evaluated in vitro and in vivo. We showed that, although substitutions at D53 did not alter MtrA's secondary structure, the MtrA D53 protein variants lost the ability to bind known MtrA recognition sequences (MtrA sites) in electrophoretic mobility shift assays. Complementation of the ΔmtrA strain with MtrA D53 protein variants did not affect overall strain growth. However, in comparison to the wild-type strain, chloramphenicol and jadomycin production were aberrant in the D53 variant strains, with levels similar to the levels in the ΔmtrA strain. Transcriptional analysis showed that the expression patterns of genes were also similar in the ΔmtrA strain and the D53 variant strains. Although the D53 protein variants and wild-type MtrA were produced at similar levels in S. venezuelae, chromatin immunoprecipitation-quantitative PCR results indicated that replacing the D53 residue rendered the altered proteins unable to bind MtrA sites in vivo, including MtrA sites that regulate genes involved in nitrogen metabolism and in chloramphenicol and jadomycin biosynthesis. In conclusion, our study demonstrates that the predicted phosphorylation site D53 is critical for the role of MtrA in regulation and suggests that MtrA functions in a phosphorylated form in the genus Streptomyces. IMPORTANCE Although phosphorylation has been shown to be essential for the activation of many response regulator proteins of two-component systems, the role of the phosphorylation site in the function of the global regulator MtrA in the genus Streptomyces has not been reported. In this study, we generated Streptomyces mutants that had amino acid substitutions at the predicted phosphorylation site of MtrA, and the effects of the substitutions were investigated by comparing the phenotypes of the resulting strains and their gene expression patterns with those of the wild-type strain and an MtrA deletion mutant. The ability of the altered proteins to bind known promoter targets in vitro was also evaluated. Our analyses showed that the predicted phosphorylation site D53 is critical for MtrA binding in vitro and for the normal functioning of MtrA in vivo. These studies further demonstrate the importance of MtrA as a global regulator in the genus Streptomyces.
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Regulation of Resistance in Vancomycin-Resistant Enterococci: The VanRS Two-Component System. Microorganisms 2021; 9:microorganisms9102026. [PMID: 34683347 PMCID: PMC8541618 DOI: 10.3390/microorganisms9102026] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 09/21/2021] [Accepted: 09/22/2021] [Indexed: 01/20/2023] Open
Abstract
Vancomycin-resistant enterococci (VRE) are a serious threat to human health, with few treatment options being available. New therapeutics are urgently needed to relieve the health and economic burdens presented by VRE. A potential target for new therapeutics is the VanRS two-component system, which regulates the expression of vancomycin resistance in VRE. VanS is a sensor histidine kinase that detects vancomycin and in turn activates VanR; VanR is a response regulator that, when activated, directs expression of vancomycin-resistance genes. This review of VanRS examines how the expression of vancomycin resistance is regulated, and provides an update on one of the field’s most pressing questions: How does VanS sense vancomycin?
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12
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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: 3] [Impact Index Per Article: 1.0] [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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13
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Methylation of two-component response regulator MtrA in mycobacteria negatively modulates its DNA binding and transcriptional activation. Biochem J 2020; 477:4473-4489. [PMID: 33175092 DOI: 10.1042/bcj20200455] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 11/05/2020] [Accepted: 11/11/2020] [Indexed: 12/23/2022]
Abstract
Post-translational modifications such as phosphorylation, nitrosylation, and pupylation modulate multiple cellular processes in Mycobacterium tuberculosis. While protein methylation at lysine and arginine residues is widespread in eukaryotes, to date only two methylated proteins in Mtb have been identified. Here, we report the identification of methylation at lysine and/or arginine residues in nine mycobacterial proteins. Among the proteins identified, we chose MtrA, an essential response regulator of a two-component signaling system, which gets methylated on multiple lysine and arginine residues to examine the functional consequences of methylation. While methylation of K207 confers a marginal decrease in the DNA-binding ability of MtrA, methylation of R122 or K204 significantly reduces the interaction with the DNA. Overexpression of S-adenosyl homocysteine hydrolase (SahH), an enzyme that modulates the levels of S-adenosyl methionine in mycobacteria decreases the extent of MtrA methylation. Most importantly, we show that decreased MtrA methylation results in transcriptional activation of mtrA and sahH promoters. Collectively, we identify novel methylated proteins, expand the list of modifications in mycobacteria by adding arginine methylation, and show that methylation regulates MtrA activity. We propose that protein methylation could be a more prevalent modification in mycobacterial proteins.
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14
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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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15
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Arora G, Bothra A, Prosser G, Arora K, Sajid A. Role of post-translational modifications in the acquisition of drug resistance in Mycobacterium tuberculosis. FEBS J 2020; 288:3375-3393. [PMID: 33021056 DOI: 10.1111/febs.15582] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Revised: 09/16/2020] [Accepted: 09/30/2020] [Indexed: 12/22/2022]
Abstract
Tuberculosis (TB) is one of the primary causes of deaths due to infectious diseases. The current TB regimen is long and complex, failing of which leads to relapse and/or the emergence of drug resistance. There is a critical need to understand the mechanisms of resistance development. With increasing drug pressure, Mycobacterium tuberculosis (Mtb) activates various pathways to counter drug-related toxicity. Signaling modules steer the evolution of Mtb to a variant that can survive, persist, adapt, and emerge as a form that is resistant to one or more drugs. Recent studies reveal that about 1/3rd of the annotated Mtb proteome is modified post-translationally, with a large number of these proteins being essential for mycobacterial survival. Post-translational modifications (PTMs) such as phosphorylation, acetylation, and pupylation play a salient role in mycobacterial virulence, pathogenesis, and metabolism. The role of many other PTMs is still emerging. Understanding the signaling pathways and PTMs may assist clinical strategies and drug development for Mtb. In this review, we explore the contribution of PTMs to mycobacterial physiology, describe the related cellular processes, and discuss how these processes are linked to drug resistance. A significant number of drug targets, InhA, RpoB, EmbR, and KatG, are modified at multiple residues via PTMs. A better understanding of drug-resistance regulons and associated PTMs will aid in developing effective drugs against TB.
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Affiliation(s)
- Gunjan Arora
- Yale School of Medicine, Yale University, New Haven, CT, USA
| | - Ankur Bothra
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Gareth Prosser
- Cancer Research UK Manchester Institute, The University of Manchester, Alderley Park, UK
| | - Kriti Arora
- Proteus Digital Health, Inc., Redwood City, CA, USA
| | - Andaleeb Sajid
- Yale School of Medicine, Yale University, New Haven, CT, USA
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16
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Xie M, Wu M, Han A. Structural insights into the signal transduction mechanism of the K +-sensing two-component system KdpDE. Sci Signal 2020; 13:13/643/eaaz2970. [PMID: 32753477 DOI: 10.1126/scisignal.aaz2970] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Two-component systems (TCSs), which consist of a histidine kinase (HK) sensor and a response regulator (RR), are important for bacteria to quickly sense and respond to various environmental signals. HKs and RRs typically function as a cognate pair, interacting only with one another to transduce signaling. Precise signal transduction in a TCS depends on the specific interactions between the receiver domain (RD) of the RR and the dimerization and histidine phosphorylation domain (DHp) of the HK. Here, we determined the complex structure of KdpDE, a TCS consisting of the HK KdpD and the RR KdpE, which is responsible for K+ homeostasis. Both the RD and the DNA binding domain (DBD) of KdpE interacted with KdpD. Although the RD of KdpE and the DHp of KdpD contributed to binding specificity, the DBD mediated a distinct interaction with the catalytic ATP-binding (CA) domain of KdpD that was indispensable for KdpDE-mediated signal transduction. Moreover, the DBD-CA interface largely overlapped with that of the DBD-DNA complex, leading to competition between KdpD and its target promoter in a KdpE phosphorylation-dependent manner. In addition, the extended C-terminal tail of the CA domain was critical for stabilizing the interaction with KdpDE and for signal transduction. Together, these data provide a molecular basis for specific KdpD and KdpE interactions that play key roles in efficient signal transduction and transcriptional regulation by this TCS.
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Affiliation(s)
- Mingquan Xie
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361102, China
| | - Mengyuan Wu
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361102, China
| | - Aidong Han
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361102, China.
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17
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Ali MM, Provoost A, Mijnendonckx K, Van Houdt R, Charlier D. DNA-Binding and Transcription Activation by Unphosphorylated Response Regulator AgrR From Cupriavidus metallidurans Involved in Silver Resistance. Front Microbiol 2020; 11:1635. [PMID: 32765465 PMCID: PMC7380067 DOI: 10.3389/fmicb.2020.01635] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 06/23/2020] [Indexed: 11/13/2022] Open
Abstract
Even though silver and silver nanoparticles at low concentrations are considered safe for human health, their steadily increasing use and associated release in nature is not without risk since it may result in the selection of silver-resistant microorganisms, thus impeding the utilization of silver as antimicrobial agent. Furthermore, increased resistance to metals may be accompanied by increased antibiotic resistance. Inactivation of the histidine kinase and concomitant upregulation of the cognate response regulator (RR) of the AgrRS two-component system was previously shown to play an important role in the increased silver resistance of laboratory adapted mutants of Cupriavidus metallidurans. However, binding of AgrR, a member of the OmpR/PhoP family of RRs with a conserved phosphoreceiver aspartate residue, to potential target promoters has never been demonstrated. Here we identify differentially expressed genes in the silver-resistant mutant NA4S in non-selective conditions by RNA-seq and demonstrate sequence-specific binding of AgrR to six selected promoter regions of upregulated genes and divergent operons. We delimit binding sites by DNase I and in gel copper-phenanthroline footprinting of AgrR-DNA complexes, and establish a high resolution base-specific contact map of AgrR-DNA interactions using premodification binding interference techniques. We identified a 16-bp core AgrR binding site (AgrR box) arranged as an imperfect inverted repeat of 6 bp (ATTACA) separated by 4 bp variable in sequence (6-4-6). AgrR interacts with two major groove segments and the intervening minor groove, all aligned on one face of the helix. Furthermore, an additional in phase imperfect direct repeat of the half-site may be observed slightly up and/or downstream of the inverted repeat at some operators. Mutant studies indicated that both inverted and direct repeats contribute to AgrR binding in vitro and AgrR-mediated activation in vivo. From the position of the AgrR box it appears that AgrR may act as a Type II activator for most investigated promoters, including positive autoregulation. Furthermore, we show in vitro binding and in vivo activation with dephosphomimetic AgrR mutant D51A, indicating that unphosphorylated AgrR is the active form of the RR in mutant NA4S.
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Affiliation(s)
- Md Muntasir Ali
- Research Group of Microbiology, Department of Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium.,Microbiology Unit, Interdisciplinary Biosciences, Belgian Nuclear Research Centre (SCK CEN), Mol, Belgium
| | - Ann Provoost
- Microbiology Unit, Interdisciplinary Biosciences, Belgian Nuclear Research Centre (SCK CEN), Mol, Belgium
| | - Kristel Mijnendonckx
- Microbiology Unit, Interdisciplinary Biosciences, Belgian Nuclear Research Centre (SCK CEN), Mol, Belgium
| | - Rob Van Houdt
- Microbiology Unit, Interdisciplinary Biosciences, Belgian Nuclear Research Centre (SCK CEN), Mol, Belgium
| | - Daniel Charlier
- Research Group of Microbiology, Department of Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium
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18
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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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19
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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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20
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Li X, Lv X, Lin Y, Zhen J, Ruan C, Duan W, Li Y, Xie J. Role of two-component regulatory systems in intracellular survival of Mycobacterium tuberculosis. J Cell Biochem 2019; 120:12197-12207. [PMID: 31026098 DOI: 10.1002/jcb.28792] [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: 11/15/2018] [Revised: 01/11/2019] [Accepted: 01/14/2019] [Indexed: 11/06/2022]
Abstract
The typical two-component regulatory systems (TCSs), consisting of response regulator and histidine kinase, play a central role in survival of pathogenic bacteria under stress conditions such as nutrient starvation, hypoxia, and nitrosative stress. A total of 11 complete paired two-component regulatory systems have been found in Mycobacterium tuberculosis, including a few isolated kinase and regulatory genes. Increasing evidence has shown that TCSs are closely associated with multiple physiological process like intracellular persistence, pathogenicity, and metabolism. This review gives the two-component signal transduction systems in M. tuberculosis and their signal transduction roles in adaption to the environment.
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Affiliation(s)
- Xue Li
- State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Institute of Modern Biopharmaceuticals, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, China
| | - Xi Lv
- State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Institute of Modern Biopharmaceuticals, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, China
| | - Yanping Lin
- State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Institute of Modern Biopharmaceuticals, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, China
| | - Junfeng Zhen
- State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Institute of Modern Biopharmaceuticals, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, China
| | - Cao Ruan
- State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Institute of Modern Biopharmaceuticals, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, China
| | - Wei Duan
- State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Institute of Modern Biopharmaceuticals, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, China
| | - Yue Li
- State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Institute of Modern Biopharmaceuticals, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, China
| | - Jianping Xie
- State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Institute of Modern Biopharmaceuticals, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, China
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21
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Singh KK, Bhardwaj N, Sankhe GD, Udaykumar N, Singh R, Malhotra V, Saini DK. Acetylation of Response Regulator Proteins, TcrX and MtrA in M. tuberculosis Tunes their Phosphotransfer Ability and Modulates Two-Component Signaling Crosstalk. J Mol Biol 2019; 431:777-793. [DOI: 10.1016/j.jmb.2019.01.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 01/01/2019] [Accepted: 01/03/2019] [Indexed: 01/31/2023]
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22
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Gorla P, Plocinska R, Sarva K, Satsangi AT, Pandeeti E, Donnelly R, Dziadek J, Rajagopalan M, Madiraju MV. MtrA Response Regulator Controls Cell Division and Cell Wall Metabolism and Affects Susceptibility of Mycobacteria to the First Line Antituberculosis Drugs. Front Microbiol 2018; 9:2839. [PMID: 30532747 PMCID: PMC6265350 DOI: 10.3389/fmicb.2018.02839] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 11/05/2018] [Indexed: 11/25/2022] Open
Abstract
The biological processes regulated by the essential response regulator MtrA and the growth conditions promoting its activation in Mycobacterium tuberculosis, a slow grower and pathogen, are largely unknown. Here, using a gain-of-function mutant, MtrAY 102C, which functions in the absence of the cognate MtrB sensor kinase, we show that the MtrA regulon includes several genes involved in the processes of cell division and cell wall metabolism. The expression of selected MtrA targets and intracellular MtrA levels were compromised under replication arrest induced by genetic manipulation and under stress conditions caused by toxic radicals. The loss of the mtrA gene in M. smegmatis, a rapid grower and non-pathogen, produced filamentous cells with branches and bulges, indicating defects in cell division and cell shape. The ΔmtrA mutant was sensitized to rifampicin and vancomycin and became more resistant to isoniazid, the first line antituberculosis drug. Our data are consistent with the proposal that MtrA controls the optimal cell division, cell wall integrity, and susceptibility to some antimycobacterial drugs.
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Affiliation(s)
- Purushotham Gorla
- Biomedical Research, The University of Texas Health Science Center, Tyler, TX, United States
| | - Renata Plocinska
- Institute of Medical Biology, Polish Academy of Sciences, Lodz, Poland
| | - Krishna Sarva
- Biomedical Research, The University of Texas Health Science Center, Tyler, TX, United States
| | - Akash T Satsangi
- Biomedical Research, The University of Texas Health Science Center, Tyler, TX, United States
| | - Emmanuel Pandeeti
- Biomedical Research, The University of Texas Health Science Center, Tyler, TX, United States
| | - Robert Donnelly
- Department of Pathology and Laboratory Medicine, Rutgers New Jersey Medical School, Newark, NJ, United States
| | - Jaroslaw Dziadek
- Institute of Medical Biology, Polish Academy of Sciences, Lodz, Poland
| | - Malini Rajagopalan
- Biomedical Research, The University of Texas Health Science Center, Tyler, TX, United States
| | - Murty V Madiraju
- Biomedical Research, The University of Texas Health Science Center, Tyler, TX, United States
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23
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Mechaly AE, Haouz A, Sassoon N, Buschiazzo A, Betton JM, Alzari PM. Conformational plasticity of the response regulator CpxR, a key player in Gammaproteobacteria virulence and drug-resistance. J Struct Biol 2018; 204:165-171. [DOI: 10.1016/j.jsb.2018.08.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 08/01/2018] [Accepted: 08/03/2018] [Indexed: 01/27/2023]
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24
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Kundu M. The role of two-component systems in the physiology of Mycobacterium tuberculosis. IUBMB Life 2018; 70:710-717. [PMID: 29885211 DOI: 10.1002/iub.1872] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 04/22/2018] [Indexed: 12/14/2022]
Abstract
Tuberculosis is a global health problem, with a third of the world's population infected with the bacillus, Mycobacterium tuberculosis. The problem is exacerbated by the emergence of multidrug resistant and extensively drug resistant strains. The search for new drug targets is therefore a priority for researchers in the field. The two-component systems (TCSs) are central to the ability of the bacterium to sense and to respond appropriately to its environment. Here we summarize current knowledge on the paired TCSs of M. tuberculosis. We discuss what is currently understood regarding the signals to which each of the sensor kinases responds, and the regulons of each of the cognate response regulators. We also discuss what is known regarding attempts to inhibit the TCSs by small molecules and project their potential as pharmacological targets for the development of novel antimycobacterial agents. © 2018 IUBMB Life, 70(8):710-717, 2018.
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25
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Glanville DG, Han L, Maule AF, Woodacre A, Thanki D, Abdullah IT, Morrissey JA, Clarke TB, Yesilkaya H, Silvaggi NR, Ulijasz AT. RitR is an archetype for a novel family of redox sensors in the streptococci that has evolved from two-component response regulators and is required for pneumococcal colonization. PLoS Pathog 2018; 14:e1007052. [PMID: 29750817 PMCID: PMC5965902 DOI: 10.1371/journal.ppat.1007052] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Revised: 05/23/2018] [Accepted: 04/23/2018] [Indexed: 01/07/2023] Open
Abstract
To survive diverse host environments, the human pathogen Streptococcus pneumoniae must prevent its self-produced, extremely high levels of peroxide from reacting with intracellular iron. However, the regulatory mechanism(s) by which the pneumococcus accomplishes this balance remains largely enigmatic, as this pathogen and other related streptococci lack all known redox-sensing transcription factors. Here we describe a two-component-derived response regulator, RitR, as the archetype for a novel family of redox sensors in a subset of streptococcal species. We show that RitR works to both repress iron transport and enable nasopharyngeal colonization through a mechanism that exploits a single cysteine (Cys128) redox switch located within its linker domain. Biochemical experiments and phylogenetics reveal that RitR has diverged from the canonical two-component virulence regulator CovR to instead dimerize and bind DNA only upon Cys128 oxidation in air-rich environments. Atomic structures show that Cys128 oxidation initiates a "helical unravelling" of the RitR linker region, suggesting a mechanism by which the DNA-binding domain is then released to interact with its cognate regulatory DNA. Expanded computational studies indicate this mechanism could be shared by many microbial species outside the streptococcus genus.
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Affiliation(s)
- David G. Glanville
- Department of Microbiology and Immunology, Loyola University Chicago; Maywood, IL, United States of America
- MRC Centre for Molecular Bacteriology and Infection (CMBI), Imperial College London, London, United Kingdom
| | - Lanlan Han
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, United States of America
| | - Andrew F. Maule
- Department of Horticulture, University of Wisconsin–Madison, Linden Drive, Madison, Wisconsin, United States of America
| | - Alexandra Woodacre
- Department of Genetics, University of Leicester, Leicester, United Kingdom
| | - Devsaagar Thanki
- Department of Genetics, University of Leicester, Leicester, United Kingdom
| | - Iman Tajer Abdullah
- Department of Infection and Immunity, University of Leicester, Leicester, United Kingdom
| | - Julie A. Morrissey
- Department of Genetics, University of Leicester, Leicester, United Kingdom
| | - Thomas B. Clarke
- MRC Centre for Molecular Bacteriology and Infection (CMBI), Imperial College London, London, United Kingdom
| | - Hasan Yesilkaya
- Department of Infection and Immunity, University of Leicester, Leicester, United Kingdom
| | - Nicholas R. Silvaggi
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, United States of America
| | - Andrew T. Ulijasz
- Department of Microbiology and Immunology, Loyola University Chicago; Maywood, IL, United States of America
- MRC Centre for Molecular Bacteriology and Infection (CMBI), Imperial College London, London, United Kingdom
- * E-mail:
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Kou X, Liu Y, Li C, Liu M, Jiang L. Dimerization and Conformational Exchanges of the Receiver Domain of Response Regulator PhoB from Escherichia coli. J Phys Chem B 2018; 122:5749-5757. [DOI: 10.1021/acs.jpcb.8b01034] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Xinhui Kou
- Key Laboratory of Magnetic Resonance in Biological Systems, National Center for Magnetic Resonance in Wuhan, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China
- Graduate University of Chinese Academy of Sciences, 19A Yuquanlu, Beijing 100049, China
| | - Yixiang Liu
- Key Laboratory of Magnetic Resonance in Biological Systems, National Center for Magnetic Resonance in Wuhan, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China
| | - Conggang Li
- Key Laboratory of Magnetic Resonance in Biological Systems, National Center for Magnetic Resonance in Wuhan, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China
| | - Maili Liu
- Key Laboratory of Magnetic Resonance in Biological Systems, National Center for Magnetic Resonance in Wuhan, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China
| | - Ling Jiang
- Key Laboratory of Magnetic Resonance in Biological Systems, National Center for Magnetic Resonance in Wuhan, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China
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27
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Türkowsky D, Esken J, Goris T, Schubert T, Diekert G, Jehmlich N, von Bergen M. A Retentive Memory of Tetrachloroethene Respiration in Sulfurospirillum halorespirans - involved Proteins and a possible link to Acetylation of a Two-Component Regulatory System. J Proteomics 2018; 181:36-46. [PMID: 29617628 DOI: 10.1016/j.jprot.2018.03.030] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 03/08/2018] [Accepted: 03/27/2018] [Indexed: 10/17/2022]
Abstract
Organohalide respiration (OHR), comprising the reductive dehalogenation of halogenated organic compounds, is subject to a unique memory effect and long-term transcriptional downregulation of the involved genes in Sulfurospirillum multivorans. Gene expression ceases slowly over approximately 100 generations in the absence of tetrachloroethene (PCE). However, the molecular mechanisms of this regulation process are not understood. We show here that Sulfurospirillum halorespirans undergoes the same type of regulation when cultivated without chlorinated ethenes for a long period of time. In addition, we compared the proteomes of S. halorespirans cells cultivated in the presence of PCE with those of cells long- and short-term cultivated with nitrate as the sole electron acceptor. Important OHR-related proteins previously unidentified in S. multivorans include a histidine kinase, a putative quinol dehydrogenase membrane protein, and a PCE-induced porin. Since for some regulatory proteins a posttranslational regulation of activity by lysine acetylations is known, we also analyzed the acetylome of S. halorespirans, revealing that 32% of the proteome was acetylated in at least one condition. The data indicate that the response regulator and the histidine kinase of a two-component system most probably involved in induction of PCE respiration are highly acetylated during short-term cultivation with nitrate in the absence of PCE. SIGNIFICANCE The so far unique long-term downregulation of organohalide respiration is now identified in a second species suggesting a broader distribution of this regulatory phenomenon. An improved protein extraction method allowed the identification of proteins most probably involved in transcriptional regulation of OHR in Sulfurospirillum spp. Our data indicate that acetylations of regulatory proteins are involved in this extreme, sustained standby-mode of metabolic enzymes in the absence of a substrate. This first published acetylome of Epsilonproteobacteria might help to study other ecologically or medically important species of this clade.
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Affiliation(s)
- Dominique Türkowsky
- Department of Molecular Systems Biology, Helmholtz Centre for Environmental Research - UFZ, Permoserstraße 15, 04318 Leipzig, Germany
| | - Jens Esken
- Department of Applied and Ecological Microbiology, Institute of Microbiology, Friedrich Schiller University, Philosophenweg 12, 07743 Jena, Germany
| | - Tobias Goris
- Department of Applied and Ecological Microbiology, Institute of Microbiology, Friedrich Schiller University, Philosophenweg 12, 07743 Jena, Germany
| | - Torsten Schubert
- Department of Applied and Ecological Microbiology, Institute of Microbiology, Friedrich Schiller University, Philosophenweg 12, 07743 Jena, Germany
| | - Gabriele Diekert
- Department of Applied and Ecological Microbiology, Institute of Microbiology, Friedrich Schiller University, Philosophenweg 12, 07743 Jena, Germany
| | - Nico Jehmlich
- Department of Molecular Systems Biology, Helmholtz Centre for Environmental Research - UFZ, Permoserstraße 15, 04318 Leipzig, Germany
| | - Martin von Bergen
- Department of Molecular Systems Biology, Helmholtz Centre for Environmental Research - UFZ, Permoserstraße 15, 04318 Leipzig, Germany; Institute of Biochemistry, Faculty of Life Sciences, University of Leipzig, Brüderstraße, 34, Germany.
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28
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Takada H, Yoshikawa H. Essentiality and function of WalK/WalR two-component system: the past, present, and future of research. Biosci Biotechnol Biochem 2018. [PMID: 29514560 DOI: 10.1080/09168451.2018.1444466] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The WalK/WalR two-component system (TCS), originally identified in Bacillus subtilis, is very highly conserved in gram-positive bacteria, including several important pathogens. The WalK/WalR TCS appears to be involved in the growth of most bacterial species encoding it. Previous studies have indicated conserved functions of this system, defining this signal transduction pathway as a crucial regulatory system for cell wall metabolism. Because of such effects on essential functions, this system is considered a potential target for anti-infective therapeutics. In this review, we discuss the role of WalK/WalR TCS in different bacterial cells, focusing on the function of the genes in its regulon as well as the variations in walRK operon structure, its auxiliary proteins, and the composition of its regulon. We also discuss recent experimental data addressing its essential function and the potential type of signal being sensed by B. subtilis. This review also focuses on the potential future research.
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Affiliation(s)
- Hiraku Takada
- Department of Life Science and Research Center for Life Science, College of Science, Rikkyo University, Tokyo, Japan.,Department of Bioscience, Tokyo University of Agriculture, Tokyo, Japan
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29
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Multisystem Analysis of Mycobacterium tuberculosis Reveals Kinase-Dependent Remodeling of the Pathogen-Environment Interface. mBio 2018; 9:mBio.02333-17. [PMID: 29511081 PMCID: PMC5845002 DOI: 10.1128/mbio.02333-17] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Tuberculosis is the leading killer among infectious diseases worldwide. Increasing multidrug resistance has prompted new approaches for tuberculosis drug development, including targeted inhibition of virulence determinants and of signaling cascades that control many downstream pathways. We used a multisystem approach to determine the effects of a potent small-molecule inhibitor of the essential Mycobacterium tuberculosis Ser/Thr protein kinases PknA and PknB. We observed differential levels of phosphorylation of many proteins and extensive changes in levels of gene expression, protein abundance, cell wall lipids, and intracellular metabolites. The patterns of these changes indicate regulation by PknA and PknB of several pathways required for cell growth, including ATP synthesis, DNA synthesis, and translation. These data also highlight effects on pathways for remodeling of the mycobacterial cell envelope via control of peptidoglycan turnover, lipid content, a SigE-mediated envelope stress response, transmembrane transport systems, and protein secretion systems. Integrated analysis of phosphoproteins, transcripts, proteins, and lipids identified an unexpected pathway whereby threonine phosphorylation of the essential response regulator MtrA decreases its DNA binding activity. Inhibition of this phosphorylation is linked to decreased expression of genes for peptidoglycan turnover, and of genes for mycolyl transferases, with concomitant changes in mycolates and glycolipids in the cell envelope. These findings reveal novel roles for PknA and PknB in regulating multiple essential cell functions and confirm that these kinases are potentially valuable targets for new antituberculosis drugs. In addition, the data from these linked multisystems provide a valuable resource for future targeted investigations into the pathways regulated by these kinases in the M. tuberculosis cell. Tuberculosis is the leading killer among infectious diseases worldwide. Increasing drug resistance threatens efforts to control this epidemic; thus, new antitubercular drugs are urgently needed. We performed an integrated, multisystem analysis of Mycobacterium tuberculosis responses to inhibition of its two essential serine/threonine protein kinases. These kinases allow the bacterium to adapt to its environment by phosphorylating cellular proteins in response to extracellular signals. We identified differentially phosphorylated proteins, downstream changes in levels of specific mRNA and protein abundance, and alterations in the metabolite and lipid content of the cell. These results include changes previously linked to growth arrest and also reveal new roles for these kinases in regulating essential processes, including growth, stress responses, transport of proteins and other molecules, and the structure of the mycobacterial cell envelope. Our multisystem data identify PknA and PknB as promising targets for drug development and provide a valuable resource for future investigation of their functions.
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Dual phosphorylation in response regulator protein PrrA is crucial for intracellular survival of mycobacteria consequent upon transcriptional activation. Biochem J 2017; 474:4119-4136. [PMID: 29101285 DOI: 10.1042/bcj20170596] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 11/02/2017] [Accepted: 11/03/2017] [Indexed: 01/05/2023]
Abstract
The remarkable ability of Mycobacterium tuberculosis (Mtb) to survive inside human macrophages is attributed to the presence of a complex sensory and regulatory network. PrrA is a DNA-binding regulatory protein, belonging to an essential two-component system (TCS), PrrA/B, which is required for early phase intracellular replication of Mtb. Despite its importance, the mechanism of PrrA/B-mediated signaling is not well understood. In the present study, we demonstrate that the binding of PrrA on the promoter DNA and its consequent activation is cumulatively controlled via dual phosphorylation of the protein. We have further characterized the role of terminal phospho-acceptor domain in the physical interaction of PrrA with its cognate kinase PrrB. The genetic deletion of prrA/B in Mycobacterium smegmatis was possible only in the presence of ectopic copies of the genes, suggesting the essentiality of this TCS in fast-growing mycobacterial strains as well. The overexpression of phospho-mimetic mutant (T6D) altered the growth of M. smegmatis in an in vitro culture and affected the replication of Mycobacterium bovis BCG in mouse peritoneal macrophages. Interestingly, the Thr6 site was found to be conserved in Mtb complex, whereas it was altered in some fast-growing mycobacterial strains, indicating that this unique phosphorylation might be predominant in employing the regulatory circuit in M. bovis BCG and presumably also in Mtb complex.
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31
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Som NF, Heine D, Holmes NA, Munnoch JT, Chandra G, Seipke RF, Hoskisson PA, Wilkinson B, Hutchings MI. The Conserved Actinobacterial Two-Component System MtrAB Coordinates Chloramphenicol Production with Sporulation in Streptomyces venezuelae NRRL B-65442. Front Microbiol 2017; 8:1145. [PMID: 28702006 PMCID: PMC5487470 DOI: 10.3389/fmicb.2017.01145] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 06/06/2017] [Indexed: 12/30/2022] Open
Abstract
Streptomyces bacteria make numerous secondary metabolites, including half of all known antibiotics. Production of antibiotics is usually coordinated with the onset of sporulation but the cross regulation of these processes is not fully understood. This is important because most Streptomyces antibiotics are produced at low levels or not at all under laboratory conditions and this makes large scale production of these compounds very challenging. Here, we characterize the highly conserved actinobacterial two-component system MtrAB in the model organism Streptomyces venezuelae and provide evidence that it coordinates production of the antibiotic chloramphenicol with sporulation. MtrAB are known to coordinate DNA replication and cell division in Mycobacterium tuberculosis where TB-MtrA is essential for viability but MtrB is dispensable. We deleted mtrB in S. venezuelae and this resulted in a global shift in the metabolome, including constitutive, higher-level production of chloramphenicol. We found that chloramphenicol is detectable in the wild-type strain, but only at very low levels and only after it has sporulated. ChIP-seq showed that MtrA binds upstream of DNA replication and cell division genes and genes required for chloramphenicol production. dnaA, dnaN, oriC, and wblE (whiB1) are DNA binding targets for MtrA in both M. tuberculosis and S. venezuelae. Intriguingly, over-expression of TB-MtrA and gain of function TB- and Sv-MtrA proteins in S. venezuelae also switched on higher-level production of chloramphenicol. Given the conservation of MtrAB, these constructs might be useful tools for manipulating antibiotic production in other filamentous actinomycetes.
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Affiliation(s)
- Nicolle F. Som
- School of Biological Sciences, University of East AngliaNorwich, United Kingdom
| | - Daniel Heine
- Department of Molecular Microbiology, John Innes CentreNorwich, United Kingdom
| | - Neil A. Holmes
- School of Biological Sciences, University of East AngliaNorwich, United Kingdom
| | - John T. Munnoch
- School of Biological Sciences, University of East AngliaNorwich, United Kingdom
| | - Govind Chandra
- Department of Molecular Microbiology, John Innes CentreNorwich, United Kingdom
| | - Ryan F. Seipke
- School of Biological Sciences, University of East AngliaNorwich, United Kingdom
- School of Molecular and Cellular Biology, Astbury Centre for Structural Molecular Biology, University of LeedsLeeds, United Kingdom
| | - Paul A. Hoskisson
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of StrathclydeGlasgow, United Kingdom
| | - Barrie Wilkinson
- Department of Molecular Microbiology, John Innes CentreNorwich, United Kingdom
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32
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Desai SK, Kenney LJ. To ∼P or Not to ∼P? Non-canonical activation by two-component response regulators. Mol Microbiol 2016; 103:203-213. [PMID: 27656860 DOI: 10.1111/mmi.13532] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/15/2016] [Indexed: 12/30/2022]
Abstract
Bacteria sense and respond to their environment through the use of two-component regulatory systems. The ability to adapt to a wide range of environmental stresses is directly related to the number of two-component systems an organism possesses. Recent advances in this area have identified numerous variations on the archetype systems that employ a sensor kinase and a response regulator. It is now evident that many orphan regulators that lack cognate kinases do not rely on phosphorylation for activation and new roles for unphosphorylated response regulators have been identified. The significance of recent findings and suggestions for further research are discussed.
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Affiliation(s)
- Stuti K Desai
- Mechanobiology Institute, 5A Engineering Drive 1, National University of Singapore, Singapore, Singapore
| | - Linda J Kenney
- Mechanobiology Institute, 5A Engineering Drive 1, National University of Singapore, Singapore, Singapore.,Jesse Brown Veteran's Administration Medical Center, Chicago, IL, USA.,Department of Microbiology & Immunology, University of Illinois-Chicago, Chicago, IL, USA
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33
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Shan S, Min H, Liu T, Jiang D, Rao Z. Structural insight into dephosphorylation by trehalose 6‐phosphate phosphatase (OtsB2) from
Mycobacterium tuberculosis. FASEB J 2016; 30:3989-3996. [DOI: 10.1096/fj.201600463r] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 08/08/2016] [Indexed: 11/11/2022]
Affiliation(s)
- Shan Shan
- National Laboratory of BiomacromoleculesInstitute of Biophysics Beijing China
| | - Haowei Min
- State Key Laboratory of Plant Genomics Beijing China
- National Center for Plant Gene Research–BeijingInstitute of Genetics and Developmental Biology Chinese Academy of Sciences Beijing China
| | - Ting Liu
- College of Life SciencesNankai University Tianjin China
| | - Dunquan Jiang
- College of Life SciencesNankai University Tianjin China
| | - Zihe Rao
- National Laboratory of BiomacromoleculesInstitute of Biophysics Beijing China
- College of Life SciencesNankai University Tianjin China
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34
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Banerjee SK, Kumar M, Alokam R, Sharma AK, Chatterjee A, Kumar R, Sahu SK, Jana K, Singh R, Yogeeswari P, Sriram D, Basu J, Kundu M. Targeting multiple response regulators of Mycobacterium tuberculosis augments the host immune response to infection. Sci Rep 2016; 6:25851. [PMID: 27181265 PMCID: PMC4867592 DOI: 10.1038/srep25851] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 04/25/2016] [Indexed: 11/06/2022] Open
Abstract
The genome of M. tuberculosis (Mtb) encodes eleven paired two component systems (TCSs) consisting of a sensor kinase (SK) and a response regulator (RR). The SKs sense environmental signals triggering RR-dependent gene expression pathways that enable the bacterium to adapt in the host milieu. We demonstrate that a conserved motif present in the C-terminal domain regulates the DNA binding functions of the OmpR family of Mtb RRs. Molecular docking studies against this motif helped to identify two molecules with a thiazolidine scaffold capable of targeting multiple RRs, and modulating their regulons to attenuate bacterial replication in macrophages. The changes in the bacterial transcriptome extended to an altered immune response with increased autophagy and NO production, leading to compromised survival of Mtb in macrophages. Our findings underscore the promise of targeting multiple RRs as a novel yet unexplored approach for development of new anti-mycobacterial agents particularly against drug-resistant Mtb.
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Affiliation(s)
- Srijon Kaushik Banerjee
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata 700009, India
| | - Manish Kumar
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata 700009, India
| | - Reshma Alokam
- Department of Pharmacy, Birla Institute of Technology &Science-Pilani, Hyderabad Campus, Jawahar Nagar, Hyderabad 500078, India
| | - Arun Kumar Sharma
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata 700009, India
| | - Ayan Chatterjee
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata 700009, India
| | - Ranjeet Kumar
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata 700009, India
| | - Sanjaya Kumar Sahu
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata 700009, India
| | - Kuladip Jana
- Division of Molecular Medicine, Bose Institute, P-1/12 CIT Scheme VII M, Kolkata 700054, India
| | - Ramandeep Singh
- Vaccine and Infectious Disease Research Centre, Translational Health Science and Technology Institute, NCR-Biotech Science Cluster, 3rd Milestone, Faridabad Gurgaon Expressway. Faridabad-121001, India
| | - Perumal Yogeeswari
- Department of Pharmacy, Birla Institute of Technology &Science-Pilani, Hyderabad Campus, Jawahar Nagar, Hyderabad 500078, India
| | - Dharmarajan Sriram
- Department of Pharmacy, Birla Institute of Technology &Science-Pilani, Hyderabad Campus, Jawahar Nagar, Hyderabad 500078, India
| | - Joyoti Basu
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata 700009, India
| | - Manikuntala Kundu
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata 700009, India
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35
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Khosa S, Hoeppner A, Gohlke H, Schmitt L, Smits SHJ. Structure of the Response Regulator NsrR from Streptococcus agalactiae, Which Is Involved in Lantibiotic Resistance. PLoS One 2016; 11:e0149903. [PMID: 26930060 PMCID: PMC4773095 DOI: 10.1371/journal.pone.0149903] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Accepted: 02/05/2016] [Indexed: 01/22/2023] Open
Abstract
Lantibiotics are antimicrobial peptides produced by Gram-positive bacteria. Interestingly, several clinically relevant and human pathogenic strains are inherently resistant towards lantibiotics. The expression of the genes responsible for lantibiotic resistance is regulated by a specific two-component system consisting of a histidine kinase and a response regulator. Here, we focused on a response regulator involved in lantibiotic resistance, NsrR from Streptococcus agalactiae, and determined the crystal structures of its N-terminal receiver domain and C-terminal DNA-binding effector domain. The C-terminal domain exhibits a fold that classifies NsrR as a member of the OmpR/PhoB subfamily of regulators. Amino acids involved in phosphorylation, dimerization, and DNA-binding were identified and demonstrated to be conserved in lantibiotic resistance regulators. Finally, a model of the full-length NsrR in the active and inactive state provides insights into protein dimerization and DNA-binding.
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Affiliation(s)
- Sakshi Khosa
- Institute of Biochemistry, Heinrich Heine University Duesseldorf, Universitaetsstr. 1, 40225, Duesseldorf, Germany
| | - Astrid Hoeppner
- X-Ray Facility and Crystal Farm, Heinrich Heine University Duesseldorf, Universitaetsstr. 1, 40225, Duesseldorf, Germany
| | - Holger Gohlke
- Institute of Pharmaceutical and Medicinal Chemistry, Heinrich Heine University Duesseldorf, Universitaetsstr. 1, 40225, Duesseldorf, Germany
| | - Lutz Schmitt
- Institute of Biochemistry, Heinrich Heine University Duesseldorf, Universitaetsstr. 1, 40225, Duesseldorf, Germany
| | - Sander H. J. Smits
- Institute of Biochemistry, Heinrich Heine University Duesseldorf, Universitaetsstr. 1, 40225, Duesseldorf, Germany
- * E-mail:
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36
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Vashist A, Prithvi Raj D, Gupta UD, Bhat R, Tyagi JS. The α10 helix of DevR, the Mycobacterium tuberculosis dormancy response regulator, regulates its DNA binding and activity. FEBS J 2016; 283:1286-99. [PMID: 26799615 DOI: 10.1111/febs.13664] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Revised: 01/05/2016] [Accepted: 01/18/2016] [Indexed: 11/26/2022]
Abstract
The crystal structures of several bacterial response regulators provide insight into the various interdomain molecular interactions potentially involved in maintaining their 'active' or 'inactive' states. However, the requirement of high concentrations of protein, an optimal pH and ionic strength buffers during crystallization may result in a structure somewhat different from that observed in solution. Therefore, functional assessment of the physiological relevance of the crystal structure data is imperative. DevR/DosR dormancy regulator of Mycobacterium tuberculosis (Mtb) belongs to the NarL subfamily of response regulators. The crystal structure of unphosphorylated DevR revealed that it forms a dimer through the α5/α6 interface. It was proposed that phosphorylation may trigger extensive structural rearrangements in DevR that culminate in the formation of a DNA-binding competent dimeric species via α10-α10 helix interactions. The α10 helix-deleted DevR protein (DevR∆α10 ) was hyperphosphorylated but defective with respect to in vitro DNA binding. Biophysical characterization reveals that DevR∆α10 has an open but less stable conformation. The combined cross-linking and DNA-binding data demonstrate that the α10 helix is essential for the formation and stabilization of the DNA-binding proficient DevR structure in both the phosphorylated and unphosphorylated states. Genetic studies establish that Mtb strains expressing DevR∆α10 are defective with respect to dormancy regulon expression under hypoxia. The present study highlights the indispensable role of the α10 helix in DevR activation and function under hypoxia and establishes the α10-α10 helix interface as a novel target for developing inhibitors against DevR, a key regulator of hypoxia-triggered dormancy.
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Affiliation(s)
- Atul Vashist
- Department of Biotechnology, All India Institute of Medical Sciences, New Delhi, India.,Experimental Animal Facility, National JALMA Institute of Leprosy and Other Mycobacterial Diseases, Tajganj, Agra, India
| | - D Prithvi Raj
- Department of Biotechnology, All India Institute of Medical Sciences, New Delhi, India
| | - Umesh Datta Gupta
- Experimental Animal Facility, National JALMA Institute of Leprosy and Other Mycobacterial Diseases, Tajganj, Agra, India
| | - Rajiv Bhat
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
| | - Jaya Sivaswami Tyagi
- Department of Biotechnology, All India Institute of Medical Sciences, New Delhi, India
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Abstract
Two-component regulatory systems (2CRSs) are widely used by bacteria to sense and respond to environmental stimuli with coordinated changes in gene expression. Systems are normally comprised of a sensory kinase protein that activates a transcriptional regulator by phosphorylation. Mycobacteria have few 2CRSs, but they are of key importance for bacterial survival and play important roles in pathogenicity. Mycobacterium tuberculosis has 12 paired two-component regulatory systems (which include a system with two regulators and one sensor, and a split sensor system), as well as four orphan regulators. Several systems are involved in virulence, and disruption of different systems leads to attenuation or hypervirulence. PhoPR plays a major role in regulating cell wall composition, and its inactivation results in sufficient attenuation of M. tuberculosis that deletion strains are live vaccine candidates. MprAB controls the stress response and is required for persistent infections. SenX3-RegX3 is required for control of aerobic respiration and phosphate uptake, and PrrAB is required for adaptation to intracellular infection. MtrAB is an essential system that controls DNA replication and cell division. The remaining systems (KdpDE, NarL, TrcRS, TcrXY, TcrA, PdtaRS, and four orphan regulators) are less well understood. The structure and binding motifs for several regulators have been characterized, revealing variations in function and operation. The sensors are less well characterized, and stimuli for many remain to be confirmed. This chapter reviews our current understanding of the role of two-component systems in mycobacteria, in particular M. tuberculosis.
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38
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Structure and dynamics of polymyxin-resistance-associated response regulator PmrA in complex with promoter DNA. Nat Commun 2015; 6:8838. [PMID: 26564787 PMCID: PMC4660055 DOI: 10.1038/ncomms9838] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 10/08/2015] [Indexed: 01/21/2023] Open
Abstract
PmrA, an OmpR/PhoB family response regulator, manages genes for antibiotic resistance. Phosphorylation of OmpR/PhoB response regulator induces the formation of a symmetric dimer in the N-terminal receiver domain (REC), promoting two C-terminal DNA-binding domains (DBDs) to recognize promoter DNA to elicit adaptive responses. Recently, determination of the KdpE-DNA complex structure revealed an REC-DBD interface in the upstream protomer that may be necessary for transcription activation. Here, we report the 3.2-Å-resolution crystal structure of the PmrA-DNA complex, which reveals a similar yet different REC-DBD interface. However, NMR studies show that in the DNA-bound state, two domains tumble separately and an REC-DBD interaction is transiently populated in solution. Reporter gene analyses of PmrA variants with altered interface residues suggest that the interface is not crucial for supporting gene expression. We propose that REC-DBD interdomain dynamics and the DBD-DBD interface help PmrA interact with RNA polymerase holoenzyme to activate downstream gene transcription.
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39
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Nguyen MP, Yoon JM, Cho MH, Lee SW. Prokaryotic 2-component systems and the OmpR/PhoB superfamily. Can J Microbiol 2015; 61:799-810. [DOI: 10.1139/cjm-2015-0345] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
In bacteria, 2-component regulatory systems (TCSs) are the critical information-processing pathways that link stimuli to specific adaptive responses. Signals perceived by membrane sensors, which are generally histidine kinases, are transmitted by response regulators (RRs) to allow cells to cope rapidly and effectively with environmental challenges. Over the past few decades, genes encoding components of TCSs and their responsive proteins have been identified, crystal structures have been described, and signaling mechanisms have been elucidated. Here, we review recent findings and interesting breakthroughs in bacterial TCS research. Furthermore, we discuss structural features, mechanisms of activation and regulation, and cross-regulation of RRs, with a focus on the largest RR family, OmpR/PhoB, to provide a comprehensive overview of these critically important signaling molecules.
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Affiliation(s)
| | - Joo-Mi Yoon
- Crop Biotech Institute, Kyung Hee University, Yongin 446-701, Korea
| | - Man-Ho Cho
- Department of Genetic Engineering and Graduate School of Biotechnology, Kyung Hee University, Yongin 446-701, Korea
| | - Sang-Won Lee
- Crop Biotech Institute, Kyung Hee University, Yongin 446-701, Korea
- Department of Genetic Engineering and Graduate School of Biotechnology, Kyung Hee University, Yongin 446-701, Korea
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Purushotham G, Sarva KB, Blaszczyk E, Rajagopalan M, Madiraju MV. Mycobacterium tuberculosis oriC sequestration by MtrA response regulator. Mol Microbiol 2015. [PMID: 26207528 DOI: 10.1111/mmi.13144] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The regulators of Mycobacterium tuberculosis DNA replication are largely unknown. Here, we demonstrate that in synchronously replicating M. tuberculosis, MtrA access to origin of replication (oriC) is enriched in the post-replication (D) period. The increased oriC binding results from elevated MtrA phosphorylation (MtrA∼P) as evidenced by reduced expression of dnaN, dnaA and increased expression of select cell division targets. Overproduction of gain-of-function MtrAY102C advanced the MtrA oriC access to the C period, reduced dnaA and dnaN expression, interfered with replication synchrony and compromised cell division. Overproduction of wild-type (MtrA+) or phosphorylation-defective MtrAD56N did not promote oriC access in the C period, nor affected cell cycle progression. MtrA interacts with DnaA signaling a possibility that DnaA helps load MtrA on oriC. Therefore, oriC sequestration by MtrA∼P in the D period may normally serve to prevent untimely initiations and that DnaA-MtrA interactions may facilitate regulated oriC replication. Finally, despite the near sequence identity of MtrA in M. smegmatis and M. tuberculosis, the M. smegmatis oriC is not MtrA-target. We conclude that M. tuberculosis oriC has evolved to be regulated by MtrA and that cell cycle progression in this organisms are governed, at least in part, by oscillations in the MtrA∼P levels.
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Affiliation(s)
- Gorla Purushotham
- Biomedical Research, The University of Health Science Center at Tyler, Tyler, TX, 75708, USA
| | - Krishna B Sarva
- Biomedical Research, The University of Health Science Center at Tyler, Tyler, TX, 75708, USA
| | - Ewelina Blaszczyk
- Biomedical Research, The University of Health Science Center at Tyler, Tyler, TX, 75708, USA
| | - Malini Rajagopalan
- Biomedical Research, The University of Health Science Center at Tyler, Tyler, TX, 75708, USA
| | - Murty V Madiraju
- Biomedical Research, The University of Health Science Center at Tyler, Tyler, TX, 75708, USA
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Fan X, Zhang X, Zhu Y, Niu L, Teng M, Sun B, Li X. Structure of the DNA-binding domain of the response regulator SaeR fromStaphylococcus aureus. ACTA ACUST UNITED AC 2015; 71:1768-76. [DOI: 10.1107/s1399004715010287] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 05/28/2015] [Indexed: 01/01/2023]
Abstract
The SaeR/S two-component regulatory system is essential for controlling the expression of many virulence factors inStaphylococcus aureus. SaeR, a member of the OmpR/PhoB family, is a response regulator with an N-terminal regulatory domain and a C-terminal DNA-binding domain. In order to elucidate how SaeR binds to the promoter regions of target genes, the crystal structure of the DNA-binding domain of SaeR (SaeRDBD) was solved at 2.5 Å resolution. The structure reveals that SaeRDBDexists as a monomer and has the canonical winged helix–turn–helix module. EMSA experiments suggested that full-length SaeR can bind to the P1 promoter and that the binding affinity is higher than that of its C-terminal DNA-binding domain. Five key residues on the winged helix–turn–helix module were verified to be important for binding to the P1 promoterin vitroand for the physiological function of SaeRin vivo.
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Ahmad A, Cai Y, Chen X, Shuai J, Han A. Conformational Dynamics of Response Regulator RegX3 from Mycobacterium tuberculosis. PLoS One 2015. [PMID: 26201027 PMCID: PMC4511772 DOI: 10.1371/journal.pone.0133389] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Two-component signal transduction systems (TCS) are vital for adaptive responses to various environmental stresses in bacteria, fungi and even plants. A TCS typically comprises of a sensor histidine kinase (SK) with its cognate response regulator (RR), which often has two domains—N terminal receiver domain (RD) and C terminal effector domain (ED). The histidine kinase phosphorylates the RD to activate the ED by promoting dimerization. However, despite significant progress on structural studies, how RR transmits activation signal from RD to ED remains elusive. Here we analyzed active to inactive transition process of OmpR/PhoB family using an active conformation of RegX3 from Mycobacterium tuberculosis as a model system by computational approaches. An inactive state of RegX3 generated from 150 ns molecular dynamic simulation has rotameric conformations of Thr79 and Tyr98 that are generally conserved in inactive RRs. Arg81 in loop β4α4 acts synergistically with loop β1α1 to change its interaction partners during active to inactive transition, potentially leading to the N-terminal movement of RegX3 helix α1. Global conformational dynamics of RegX3 is mainly dependent on α4β5 region, in particular seven ‘hot-spot’ residues (Tyr98 to Ser104), adjacent to which several coevolved residues at dimeric interface, including Ile76-Asp96, Asp97-Arg111 and Glu24-Arg113 pairs, are critical for signal transduction. Taken together, our computational analyses suggest a molecular linkage between Asp phosphorylation, proximal loops and α4β5α5 dimeric interface during RR active to inactive state transition, which is not often evidently defined from static crystal structures.
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Affiliation(s)
- Ashfaq Ahmad
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiangan, Xiamen, China
| | - Yongfei Cai
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiangan, Xiamen, China
| | - Xingqiang Chen
- Department of Physics, Xiamen University, Siming, Xiamen, China
| | - Jianwei Shuai
- Department of Physics, Xiamen University, Siming, Xiamen, China
| | - Aidong Han
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiangan, Xiamen, China
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Satsangi AT, Pandeeti EP, Sarva K, Rajagopalan M, Madiraju MV. Mycobacterium tuberculosis MtrAY102C is a gain-of-function mutant that potentially acts as a constitutively active protein. Tuberculosis (Edinb) 2014; 93 Suppl:S28-32. [PMID: 24388645 DOI: 10.1016/s1472-9792(13)70007-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The MtrAB histidine-aspartate signal transduction of mycobacteria includes the response regulator MtrA and sensor kinase MtrB. We recently showed that Mycobacterium smegmatis ΔmtrB is filamentous, defective for cell division, cell shape maintenance and shows compromised MtrA target gene expression. Interestingly, overproduction of phosphorylation competent M. tuberculosis MtrAY102C reverses the ΔmtrB mutant phenotype, although the genetic basis of phenotype reversal is unknown. Here we show that introduction of D56N mutation in MtrAY102C completely abolished its phosphorylation potential yet the double mutant protein retained a partial ability to reverse the mtrB mutant phenotype indicating that phosphorylation activity is not necessary for the function of MtrAY102C. The phosphorylation-defective MtrAD56N-Y102C protein bound its target promoters ripA and fbpB efficiently. Together, these results support a hypothesis that the gain-of-function phenotype of MtrAY102C is in part due to its ability to function as a constitutively active protein in the absence of phosphorylation.
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Affiliation(s)
- Akash T Satsangi
- Biomedical Research, The University of Texas Health Science Center @ Tyler, 11937 U.S. Hwy@ 271, Tyler, TX- 75708-3154, USA
| | - Emmanuel P Pandeeti
- Biomedical Research, The University of Texas Health Science Center @ Tyler, 11937 U.S. Hwy@ 271, Tyler, TX- 75708-3154, USA
| | - Krishna Sarva
- Biomedical Research, The University of Texas Health Science Center @ Tyler, 11937 U.S. Hwy@ 271, Tyler, TX- 75708-3154, USA
| | - Malini Rajagopalan
- Biomedical Research, The University of Texas Health Science Center @ Tyler, 11937 U.S. Hwy@ 271, Tyler, TX- 75708-3154, USA
| | - Murty V Madiraju
- Biomedical Research, The University of Texas Health Science Center @ Tyler, 11937 U.S. Hwy@ 271, Tyler, TX- 75708-3154, USA.
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Hassan SS, Tiwari S, Guimarães LC, Jamal SB, Folador E, Sharma NB, de Castro Soares S, Almeida S, Ali A, Islam A, Póvoa FD, de Abreu VAC, Jain N, Bhattacharya A, Juneja L, Miyoshi A, Silva A, Barh D, Turjanski AG, Azevedo V, Ferreira RS. Proteome scale comparative modeling for conserved drug and vaccine targets identification in Corynebacterium pseudotuberculosis. BMC Genomics 2014; 15 Suppl 7:S3. [PMID: 25573232 PMCID: PMC4243142 DOI: 10.1186/1471-2164-15-s7-s3] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Corynebacterium pseudotuberculosis (Cp) is a pathogenic bacterium that causes caseous lymphadenitis (CLA), ulcerative lymphangitis, mastitis, and edematous to a broad spectrum of hosts, including ruminants, thereby threatening economic and dairy industries worldwide. Currently there is no effective drug or vaccine available against Cp. To identify new targets, we adopted a novel integrative strategy, which began with the prediction of the modelome (tridimensional protein structures for the proteome of an organism, generated through comparative modeling) for 15 previously sequenced C. pseudotuberculosis strains. This pan-modelomics approach identified a set of 331 conserved proteins having 95-100% intra-species sequence similarity. Next, we combined subtractive proteomics and modelomics to reveal a set of 10 Cp proteins, which may be essential for the bacteria. Of these, 4 proteins (tcsR, mtrA, nrdI, and ispH) were essential and non-host homologs (considering man, horse, cow and sheep as hosts) and satisfied all criteria of being putative targets. Additionally, we subjected these 4 proteins to virtual screening of a drug-like compound library. In all cases, molecules predicted to form favorable interactions and which showed high complementarity to the target were found among the top ranking compounds. The remaining 6 essential proteins (adk, gapA, glyA, fumC, gnd, and aspA) have homologs in the host proteomes. Their active site cavities were compared to the respective cavities in host proteins. We propose that some of these proteins can be selectively targeted using structure-based drug design approaches (SBDD). Our results facilitate the selection of C. pseudotuberculosis putative proteins for developing broad-spectrum novel drugs and vaccines. A few of the targets identified here have been validated in other microorganisms, suggesting that our modelome strategy is effective and can also be applicable to other pathogens.
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Lin W, Wang Y, Han X, Zhang Z, Wang C, Wang J, Yang H, Lu Y, Jiang W, Zhao GP, Zhang P. Atypical OmpR/PhoB subfamily response regulator GlnR of actinomycetes functions as a homodimer, stabilized by the unphosphorylated conserved Asp-focused charge interactions. J Biol Chem 2014; 289:15413-25. [PMID: 24733389 DOI: 10.1074/jbc.m113.543504] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The OmpR/PhoB subfamily protein GlnR of actinomycetes is an orphan response regulator that globally coordinates the expression of genes related to nitrogen metabolism. Biochemical and genetic analyses reveal that the functional GlnR from Amycolatopsis mediterranei is unphosphorylated at the potential phosphorylation Asp(50) residue in the N-terminal receiver domain. The crystal structure of this receiver domain demonstrates that it forms a homodimer through the α4-β5-α5 dimer interface highly similar to the phosphorylated typical response regulator, whereas the so-called "phosphorylation pocket" is not conserved, with its space being occupied by an Arg(52) from the β3-α3 loop. Both in vitro and in vivo experiments confirm that GlnR forms a functional homodimer via its receiver domain and suggest that the charge interactions of Asp(50) with the highly conserved Arg(52) and Thr(9) in the receiver domain may be crucial in maintaining the proper conformation for homodimerization, as also supported by molecular dynamics simulations of the wild type GlnR versus the deficient mutant GlnR(D50A). This model is backed by the distinct phenotypes of the total deficient GlnR(R52A/T9A) double mutant versus the single mutants of GlnR (i.e. D50N, D50E, R52A and T9A), which have only minor effects upon both dimerization and physiological function of GlnR in vivo, albeit their DNA binding ability is weakened compared with that of the wild type. By integrating the supportive data of GlnRs from the model Streptomyces coelicolor and the pathogenic Mycobacterium tuberculosis, we conclude that the actinomycete GlnR is atypical with respect to its unphosphorylated conserved Asp residue being involved in the critical Arg/Asp/Thr charge interactions, which is essential for maintaining the biologically active homodimer conformation.
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Affiliation(s)
- Wei Lin
- From the Chinese Academy of Sciences Key Laboratory of Synthetic Biology
| | - Ying Wang
- From the Chinese Academy of Sciences Key Laboratory of Synthetic Biology, the State Key Laboratory of Genetic Engineering, Department of Microbiology and Microbial Engineering, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Xiaobiao Han
- From the Chinese Academy of Sciences Key Laboratory of Synthetic Biology
| | - Zilong Zhang
- From the Chinese Academy of Sciences Key Laboratory of Synthetic Biology
| | - Chengyuan Wang
- State Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Jin Wang
- From the Chinese Academy of Sciences Key Laboratory of Synthetic Biology
| | - Huaiyu Yang
- the Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Yinhua Lu
- From the Chinese Academy of Sciences Key Laboratory of Synthetic Biology
| | - Weihong Jiang
- From the Chinese Academy of Sciences Key Laboratory of Synthetic Biology
| | - Guo-Ping Zhao
- From the Chinese Academy of Sciences Key Laboratory of Synthetic Biology, the State Key Laboratory of Genetic Engineering, Department of Microbiology and Microbial Engineering, School of Life Sciences, Fudan University, Shanghai 200433, China, the Shanghai-MOST Key Laboratory of Disease and Health Genomics, Chinese National Human Genome Center at Shanghai, Shanghai 201203, China, the Department of Microbiology and Li Ka Shing Institute of Health Sciences, Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong SAR, China, and
| | - Peng Zhang
- From the Chinese Academy of Sciences Key Laboratory of Synthetic Biology, State Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China,
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Boudes M, Sanchez D, Graille M, van Tilbeurgh H, Durand D, Quevillon-Cheruel S. Structural insights into the dimerization of the response regulator ComE from Streptococcus pneumoniae. Nucleic Acids Res 2014; 42:5302-13. [PMID: 24500202 PMCID: PMC4005675 DOI: 10.1093/nar/gku110] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Revised: 01/09/2014] [Accepted: 01/13/2014] [Indexed: 12/18/2022] Open
Abstract
Natural transformation contributes to the maintenance and to the evolution of the bacterial genomes. In Streptococcus pneumoniae, this function is reached by achieving the competence state, which is under the control of the ComD-ComE two-component system. We present the crystal and solution structures of ComE. We mimicked the active and non-active states by using the phosphorylated mimetic ComE(D58E) and the unphosphorylatable ComE(D58A) mutants. In the crystal, full-length ComE(D58A) dimerizes through its canonical REC receiver domain but with an atypical mode, which is also adopted by the isolated REC(D58A) and REC(D58E). The LytTR domain adopts a tandem arrangement consistent with the two direct repeats of its promoters. However ComE(D58A) is monomeric in solution, as seen by SAXS, by contrast to ComE(D58E) that dimerizes. For both, a relative mobility between the two domains is assumed. Based on these results we propose two possible ways for activation of ComE by phosphorylation.
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Affiliation(s)
- Marion Boudes
- Institut de Biochimie et de Biophysique Moléculaire et Cellulaire, Université de Paris-Sud XI, UMR8619, Bât 430, 91405 Orsay, France and Centre National de la Recherche Scientifique, Orsay, 91405, France
| | - Dyana Sanchez
- Institut de Biochimie et de Biophysique Moléculaire et Cellulaire, Université de Paris-Sud XI, UMR8619, Bât 430, 91405 Orsay, France and Centre National de la Recherche Scientifique, Orsay, 91405, France
| | - Marc Graille
- Institut de Biochimie et de Biophysique Moléculaire et Cellulaire, Université de Paris-Sud XI, UMR8619, Bât 430, 91405 Orsay, France and Centre National de la Recherche Scientifique, Orsay, 91405, France
| | - Herman van Tilbeurgh
- Institut de Biochimie et de Biophysique Moléculaire et Cellulaire, Université de Paris-Sud XI, UMR8619, Bât 430, 91405 Orsay, France and Centre National de la Recherche Scientifique, Orsay, 91405, France
| | - Dominique Durand
- Institut de Biochimie et de Biophysique Moléculaire et Cellulaire, Université de Paris-Sud XI, UMR8619, Bât 430, 91405 Orsay, France and Centre National de la Recherche Scientifique, Orsay, 91405, France
| | - Sophie Quevillon-Cheruel
- Institut de Biochimie et de Biophysique Moléculaire et Cellulaire, Université de Paris-Sud XI, UMR8619, Bât 430, 91405 Orsay, France and Centre National de la Recherche Scientifique, Orsay, 91405, France
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Barta ML, Hickey JM, Anbanandam A, Dyer K, Hammel M, Hefty PS. Atypical response regulator ChxR from Chlamydia trachomatis is structurally poised for DNA binding. PLoS One 2014; 9:e91760. [PMID: 24646934 PMCID: PMC3960148 DOI: 10.1371/journal.pone.0091760] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Accepted: 02/14/2014] [Indexed: 01/23/2023] Open
Abstract
ChxR is an atypical two-component signal transduction response regulator (RR) of the OmpR/PhoB subfamily encoded by the obligate intracellular bacterial pathogen Chlamydia trachomatis. Despite structural homology within both receiver and effector domains to prototypical subfamily members, ChxR does not require phosphorylation for dimer formation, DNA binding or transcriptional activation. Thus, we hypothesized that ChxR is in a conformation optimal for DNA binding with limited interdomain interactions. To address this hypothesis, the NMR solution structure of the ChxR effector domain was determined and used in combination with the previously reported ChxR receiver domain structure to generate a full-length dimer model based upon SAXS analysis. Small-angle scattering of ChxR supported a dimer with minimal interdomain interactions and effector domains in a conformation that appears to require only subtle reorientation for optimal major/minor groove DNA interactions. SAXS modeling also supported that the effector domains were in a head-to-tail conformation, consistent with ChxR recognizing tandem DNA repeats. The effector domain structure was leveraged to identify key residues that were critical for maintaining protein - nucleic acid interactions. In combination with prior analysis of the essential location of specific nucleotides for ChxR recognition of DNA, a model of the full-length ChxR dimer bound to its cognate cis-acting element was generated.
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Affiliation(s)
- Michael L. Barta
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas, United States of America
| | - John M. Hickey
- Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, Kansas, United States of America
| | - Asokan Anbanandam
- Del Shankel Structural Biology Center, University of Kansas, Lawrence, Kansas, United States of America
| | - Kevin Dyer
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
| | - Michal Hammel
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
| | - P. Scott Hefty
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas, United States of America
- * E-mail:
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Narayanan A, Kumar S, Evrard AN, Paul LN, Yernool DA. An asymmetric heterodomain interface stabilizes a response regulator-DNA complex. Nat Commun 2014; 5:3282. [PMID: 24526190 PMCID: PMC4399498 DOI: 10.1038/ncomms4282] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Accepted: 01/18/2014] [Indexed: 01/08/2023] Open
Abstract
Two-component signal transduction systems consist of pairs of histidine kinases and response regulators, which mediate adaptive responses to environmental cues. Most activated response regulators regulate transcription by binding tightly to promoter DNA via a phosphorylation-triggered inactive-to-active transition. The molecular basis for formation of stable response regulator-DNA complexes that precede the assembly of RNA polymerases is unclear. Here, we present structures of DNA complexed with the response regulator KdpE, a member of the OmpR/PhoB family. The distinctively asymmetric complex in an active-like conformation reveals a unique intramolecular interface between the receiver domain (RD) and the DNA-binding domain (DBD) of only one of the two response regulators in the complex. Structure-function studies show that this RD-DBD interface is necessary to form stable complexes that support gene expression. The conservation of sequence and structure suggests that these findings extend to a large group of response regulators that act as transcription factors.
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Affiliation(s)
- Anoop Narayanan
- 1] Department of Biological Sciences, Purdue University, 915 West State Street, West Lafayette, Indiana 47907, USA [2]
| | - Shivesh Kumar
- 1] Department of Biological Sciences, Purdue University, 915 West State Street, West Lafayette, Indiana 47907, USA [2] [3]
| | - Amanda N Evrard
- Department of Biological Sciences, Purdue University, 915 West State Street, West Lafayette, Indiana 47907, USA
| | - Lake N Paul
- Bindley Bioscience Center, Purdue University, 1203 West State Street, West Lafayette, Indiana 47907, USA
| | - Dinesh A Yernool
- 1] Department of Biological Sciences, Purdue University, 915 West State Street, West Lafayette, Indiana 47907, USA [2] Bindley Bioscience Center, Purdue University, 1203 West State Street, West Lafayette, Indiana 47907, USA
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Lou YC, Wang I, Rajasekaran M, Kao YF, Ho MR, Hsu STD, Chou SH, Wu SH, Chen C. Solution structure and tandem DNA recognition of the C-terminal effector domain of PmrA from Klebsiella pneumoniae. Nucleic Acids Res 2013; 42:4080-93. [PMID: 24371275 PMCID: PMC3973317 DOI: 10.1093/nar/gkt1345] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Klebsiella pneumoniae PmrA is a polymyxin-resistance-associated response regulator. The C-terminal effector/DNA-binding domain of PmrA (PmrAC) recognizes tandem imperfect repeat sequences on the promoters of genes to induce antimicrobial peptide resistance after phosphorylation and dimerization of its N-terminal receiver domain (PmrAN). However, structural information concerning how phosphorylation of the response regulator enhances DNA recognition remains elusive. To gain insights, we determined the nuclear magnetic resonance solution structure of PmrAC and characterized the interactions between PmrAC or BeF3(-)-activated full-length PmrA (PmrAF) and two DNA sequences from the pbgP promoter of K. pneumoniae. We showed that PmrAC binds to the PmrA box, which was verified to contain two half-sites, 5'-CTTAAT-3' and 5'-CCTAAG-3', in a head-to-tail fashion with much stronger affinity to the first than the second site without cooperativity. The structural basis for the PmrAC-DNA complex was investigated using HADDOCK docking and confirmed by paramagnetic relaxation enhancement. Unlike PmrAC, PmrAF recognizes the two sites simultaneously and specifically. In the PmrAF-DNA complex, PmrAN may maintain an activated homodimeric conformation analogous to that in the free form and the interactions between two PmrAC molecules aid in bending and binding of the DNA duplex for transcription activation.
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Affiliation(s)
- Yuan-Chao Lou
- Institute of Biomedical Sciences, Institute of Biological Chemistry, Academia Sinica, Taipei 115, Institute of Biochemistry and Agricultural Biotechnology Center, National Chung Hsing University, Taichung 40227, Taiwan, Republic of China
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50
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Choudhury HG, Beis K. The dimeric form of the unphosphorylated response regulator BaeR. Protein Sci 2013; 22:1287-93. [PMID: 23868292 DOI: 10.1002/pro.2311] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Revised: 07/05/2013] [Accepted: 07/08/2013] [Indexed: 11/09/2022]
Abstract
Bacterial response regulators (RRs) can regulate the expression of genes that confer antibiotic resistance; they contain a receiver and an effector domain and their ability to bind DNA is based on the dimerization state. This is triggered by phosphorylation of the receiver domain by a kinase. However, even in the absence of phosphorylation RRs can exist in equilibrium between monomers and dimers with phosphorylation shifting the equilibrium toward the dimer form. We have determined the crystal structure of the unphosphorylated dimeric BaeR from Escherichia coli. The dimer interface is formed by a domain swap at the receiver domain. In comparison with the unphosphorylated dimeric PhoP from Mycobacterium tuberculosis, BaeR displays an asymmetry of the effector domains.
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Affiliation(s)
- Hassanul G Choudhury
- Division of Molecular Biosciences, Imperial College London, London, South Kensington, SW7 2AZ, United Kingdom; Membrane Protein Lab, Diamond Light Source, Harwell Science and Innovation Campus, Chilton, Oxfordshire, OX11 0DE, United Kingdom; Research Complex at Harwell, Harwell Oxford, Didcot, Oxforsdhire OX11 0FA, United Kingdom
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