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Sidarta M, Lorente Martín AI, Monsalve A, Marinho Righetto G, Schäfer AB, Wenzel M. Lipid phase separation impairs membrane thickness sensing by the Bacillus subtilis sensor kinase DesK. Microbiol Spectr 2024; 12:e0392523. [PMID: 38717171 PMCID: PMC11237406 DOI: 10.1128/spectrum.03925-23] [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: 11/12/2023] [Accepted: 04/08/2024] [Indexed: 06/06/2024] Open
Abstract
Membrane fluidity and thickness have emerged as crucial factors for the activity of and resistance to several antimicrobials. However, the lack of tools to study membrane fluidity and, in particular, thickness in living bacteria limits our understanding of this interplay. The Bacillus subtilis histidine kinase/phosphatase DesK is a molecular sensor that directly detects membrane thickness. It controls activity of DesR, which regulates expression of the lipid desaturase Des, known for its role in cold adaptation and daptomycin susceptibility. We hypothesized that this property could be exploited to develop biosensors and reporters for antibiotic-induced changes in membrane fluidity and thickness. To test this, we designed three assays based on the des system: activation of the Pdes promoter as reporter for membrane thickening, localization of DesK-GFP(green-fluorescent protein) as proxy for rigidified membrane domains, and antibiotic sensitivity of des, desK, and desR deletion mutants as readout for the importance of membrane rigidification/thickening under the tested condition. While we could not confirm the suitability of the des system as reporter for antibiotic-induced changes in membrane thickness, we did observe that des expression is only activated by mild temperature shocks, likely due to partitioning of the sensor DesK into fluid membrane domains upon phase separation, precluding effective thickness sensing under harsh cold shock and antibiotic stress conditions. Similarly, we did not observe any sensitivity of the deletion mutants to either temperature or antibiotic stress, raising the question to what extent the des system contributes to fluidity adaptation under these conditions. IMPORTANCE The B. subtilis des system is a prime model for direct molecular membrane thickness sensor and, as such, has been well studied in vitro. Our study shows that our understanding of its function in vivo and its importance under temperature and antibiotic stress is still very limited. Specifically, our results suggest that (i) the des system senses very subtle membrane fluidity changes that escape detection by established fluidity reporters like laurdan; (ii) membrane thickness sensing by DesK is impaired by phase separation due to partitioning of the protein into the fluid phase; and (iii) fluidity adaptations by Des are too subtle to elicit growth defects under rigidifying conditions, raising the question of how much the des system contributes to adaptation of overall membrane fluidity.
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Affiliation(s)
- Margareth Sidarta
- Division of Chemical Biology, Department of Life Sciences, Chalmers University of Technology, Gothenburg, Sweden
- Centre for Antibiotic Resistance Research in Gothenburg (CARe), Gothenburg, Sweden
| | - Ana I. Lorente Martín
- Division of Chemical Biology, Department of Life Sciences, Chalmers University of Technology, Gothenburg, Sweden
| | - Anuntxi Monsalve
- Division of Chemical Biology, Department of Life Sciences, Chalmers University of Technology, Gothenburg, Sweden
| | - Gabriela Marinho Righetto
- Division of Chemical Biology, Department of Life Sciences, Chalmers University of Technology, Gothenburg, Sweden
- Centre for Antibiotic Resistance Research in Gothenburg (CARe), Gothenburg, Sweden
| | - Ann-Britt Schäfer
- Division of Chemical Biology, Department of Life Sciences, Chalmers University of Technology, Gothenburg, Sweden
- Centre for Antibiotic Resistance Research in Gothenburg (CARe), Gothenburg, Sweden
| | - Michaela Wenzel
- Division of Chemical Biology, Department of Life Sciences, Chalmers University of Technology, Gothenburg, Sweden
- Centre for Antibiotic Resistance Research in Gothenburg (CARe), Gothenburg, Sweden
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Xu CG, Yang LX, Zhu R, Zhang J, Li Y, Chao CF. Differential analysis of transcriptome of psychrophilic bacteria under different culture temperatures. Technol Health Care 2024; 32:2251-2264. [PMID: 38517814 PMCID: PMC11322704 DOI: 10.3233/thc-231022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Accepted: 11/14/2023] [Indexed: 03/24/2024]
Abstract
BACKGROUND Psychrophilic bacteria can survive in a unique living environment. OBJECTIVE To explore the mechanism of low temperature adaptation and the physiological function of thermophilic metabolic genes. METHOD Serratia marcescens strain F13 stored in microbial laboratory was cultured at 5∘C, 10∘C and 25∘C respectively, and the obtained strains were sequenced by high-throughput transcriptome. Serratia marcescens strain CAV1761 was used as the reference strain. The data produced by transcriptome sequencing were statistically analyzed by biostatistics software such as soapnuke, soap and edger. The differentially expressed genes were found based on the gene expression, and analyzed by Gene Ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. RESULTS The results showed that there were 718 differential genes in F13-10 vs F13-5 comparison group, 1614 differential genes in F13-25 vs F13-5 comparison group and 1636 differential genes in F13-25 vs F13-10 comparison group. GO function enrichment analysis showed that the GO term mainly enriched by different genes in the three comparison groups was mostly related to the migration and transport of cellular or subcellular components, cell localization and transmembrane transporter activity, as well as cilia or flagella dependent cell movement. In the enrichment analysis of KEGG pathway, the three comparison groups all enriched the largest number of differential genes in the branch pathway of KEGG metabolism, followed by the branch pathway of environmental information processing. CONCLUSION In F13-10 vs F13-5, the differential genes were mainly concentrated in 20 pathways such as ATP-binding cassette transport (ABC) transporters, thiamine metabolism and flagella assembly; In F13-25 vs F13-5, the differential genes are mainly concentrated in 20 pathways, such as (ABC) transporters, arginine and proline metabolism, two-component system and so on; In F13-25 vs F13-10, the differential genes are mainly concentrated in 20 pathways such as various types of glycan synthesis, two-component system and arginine metabolism.
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Affiliation(s)
- Chun-Guang Xu
- Corresponding author: Chun-Guang Xu, Department of Life Science, Hulunbuir University, No. 561 Kangju Community, Xiushui Road, Hailar District, Hulunbuir, Inner Mongolia 021008, China. Tel.: +86 13847093905; E-mail:
| | | | - Rui Zhu
- Department of Life Science, Hulunbuir University, Hulunbuir, China
| | - Jie Zhang
- Department of Life Science, Hulunbuir University, Hulunbuir, China
| | - Yan Li
- Department of Life Science, Hulunbuir University, Hulunbuir, China
| | - Chun-Fang Chao
- Department of Life Science, Hulunbuir University, Hulunbuir, China
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Liu N, Jiang T, Cui WP, Qi XQ, Li XG, Lu Y, Wu LF, Zhang WJ. The TorRS two component system regulates expression of TMAO reductase in response to high hydrostatic pressure in Vibrio fluvialis. Front Microbiol 2023; 14:1291578. [PMID: 38029070 PMCID: PMC10662104 DOI: 10.3389/fmicb.2023.1291578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2023] [Accepted: 10/25/2023] [Indexed: 12/01/2023] Open
Abstract
High hydrostatic pressure (HHP) regulated gene expression is one of the most commonly adopted strategies for microbial adaptation to the deep-sea environments. Previously we showed that the HHP-inducible trimethylamine N-oxide (TMAO) reductase improves the pressure tolerance of deep-sea strain Vibrio fluvialis QY27. Here, we investigated the molecular mechanism of HHP-responsive regulation of TMAO reductase TorA. By constructing torR and torS deletion mutants, we demonstrated that the two-component regulator TorR and sensor TorS are responsible for the HHP-responsive regulation of torA. Unlike known HHP-responsive regulatory system, the abundance of torR and torS was not affected by HHP. Complementation of the ΔtorS mutant with TorS altered at conserved phosphorylation sites revealed that the three sites were indispensable for substrate-induced regulation, but only the histidine located in the alternative transmitter domain was involved in pressure-responsive regulation. Taken together, we demonstrated that the induction of TMAO reductase by HHP is mediated through the TorRS system and proposed a bifurcation of signal transduction in pressure-responsive regulation from the substrate-induction. This work provides novel knowledge of the pressure regulated gene expression and will promote the understanding of the microbial adaptation to the deep-sea HHP environment.
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Affiliation(s)
- Na Liu
- Laboratory of Deep-Sea Microbial Cell Biology, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Ting Jiang
- Laboratory of Deep-Sea Microbial Cell Biology, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Wen-Peng Cui
- Laboratory of Deep-Sea Microbial Cell Biology, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Xiao-Qing Qi
- Laboratory of Deep-Sea Microbial Cell Biology, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, China
- Institution of Deep-sea Life Sciences, IDSSE-BGI, Sanya, China
- International Associated Laboratory of Evolution and Development of Magnetotactic Multicellular Organisms, CAS, Sanya, China
| | - Xue-Gong Li
- Laboratory of Deep-Sea Microbial Cell Biology, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, China
- Institution of Deep-sea Life Sciences, IDSSE-BGI, Sanya, China
- International Associated Laboratory of Evolution and Development of Magnetotactic Multicellular Organisms, CAS, Sanya, China
| | - Yuan Lu
- College of Information Science & Engineering, Ocean University of China, Qingdao, China
| | - Long-Fei Wu
- International Associated Laboratory of Evolution and Development of Magnetotactic Multicellular Organisms, CAS, Sanya, China
- Aix Marseille University, CNRS, LCB, Marseille, France
| | - Wei-Jia Zhang
- Laboratory of Deep-Sea Microbial Cell Biology, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, China
- Institution of Deep-sea Life Sciences, IDSSE-BGI, Sanya, China
- International Associated Laboratory of Evolution and Development of Magnetotactic Multicellular Organisms, CAS, Sanya, China
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Li T, Huang J, Yang S, Chen J, Yao Z, Zhong M, Zhong X, Ye X. Pan-Genome-Wide Association Study of Serotype 19A Pneumococci Identifies Disease-Associated Genes. Microbiol Spectr 2023; 11:e0407322. [PMID: 37358412 PMCID: PMC10433855 DOI: 10.1128/spectrum.04073-22] [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: 10/06/2022] [Accepted: 06/04/2023] [Indexed: 06/27/2023] Open
Abstract
Despite the widespread implementation of pneumococcal vaccines, hypervirulent Streptococcus pneumoniae serotype 19A is endemic worldwide. It is still unclear whether specific genetic elements contribute to complex pathogenicity of serotype 19A isolates. We performed a large-scale pan-genome-wide association study (pan-GWAS) of 1,292 serotype 19A isolates sampled from patients with invasive disease and asymptomatic carriers. To address the underlying disease-associated genotypes, a comprehensive analysis using three methods (Scoary, a linear mixed model, and random forest) was performed to compare disease and carriage isolates to identify genes consistently associated with disease phenotype. By using three pan-GWAS methods, we found consensus on statistically significant associations between genotypes and disease phenotypes (disease or carriage), with a subset of 30 consistently significant disease-associated genes. The results of functional annotation revealed that these disease-associated genes had diverse predicted functions, including those that participated in mobile genetic elements, antibiotic resistance, virulence, and cellular metabolism. Our findings suggest the multifactorial pathogenicity nature of this hypervirulent serotype and provide important evidence for the design of novel protein-based vaccines to prevent and control pneumococcal disease. IMPORTANCE It is important to understand the genetic and pathogenic characteristics of S. pneumoniae serotype 19A, which may provide important information for the prevention and treatment of pneumococcal disease. This global large-sample pan-GWAS study has identified a subset of 30 consistently significant disease-associated genes that are involved in mobile genetic elements, antibiotic resistance, virulence, and cellular metabolism. These findings suggest the multifactorial pathogenicity nature of hypervirulent S. pneumoniae serotype 19A isolates and provide implications for the design of novel protein-based vaccines.
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Affiliation(s)
- Ting Li
- School of Public Health, Guangdong Pharmaceutical University, Guangzhou, China
| | - Jiayin Huang
- School of Public Health, Guangdong Pharmaceutical University, Guangzhou, China
| | - Shimin Yang
- School of Public Health, Guangdong Pharmaceutical University, Guangzhou, China
| | - Jianyu Chen
- School of Public Health, Guangdong Pharmaceutical University, Guangzhou, China
| | - Zhenjiang Yao
- School of Public Health, Guangdong Pharmaceutical University, Guangzhou, China
| | - Minghao Zhong
- Department of Prevention and Health Care, The Sixth People’s Hospital of Dongguan City, Guangdong, China
| | - Xinguang Zhong
- Department of Prevention and Health Care, The Sixth People’s Hospital of Dongguan City, Guangdong, China
| | - Xiaohua Ye
- School of Public Health, Guangdong Pharmaceutical University, Guangzhou, China
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Zhang S, Hill RT, Wang H. Genomic characterization and molecular dating of the novel bacterium Permianibacter aggregans HW001 T, which originated from Permian ground water. MARINE LIFE SCIENCE & TECHNOLOGY 2023; 5:12-27. [PMID: 37077290 PMCID: PMC10077173 DOI: 10.1007/s42995-023-00164-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 12/28/2022] [Indexed: 05/03/2023]
Abstract
The Permian Basin is a unique ecosystem located in the southwest of the USA. An unanswered question is whether the bacteria in the Permian Basin adapted to the changing paleomarine environment and survived in the remnants of Permian groundwater. In our previous study, a novel bacterial strain, Permianibacter aggregans HW001T, was isolated from microalgae cultures incubated with Permian Basin waters, and was shown to originate from the Permian Ocean. In this study, strain HW001T was shown to be the representative strain of a novel family, classified as 'Permianibacteraceae'. The results of molecular dating suggested that the strain HW001T diverged ~ 447 million years ago (mya), which is the early Permian period (~ 250 mya). Genome analysis was used to access its potential energy utilization and biosynthesis capacity. A large number of transporters, carbohydrate-active enzymes and protein-degradation related genes have been annotated in the genome of strain HW001T. In addition, a series of important metabolic pathways, such as peptidoglycan biosynthesis, osmotic stress response system and multifunctional quorum sensing were annotated, which may confer the ability to adapt to various unfavorable environmental conditions. Finally, the evolutionary history of strain HW001T was reconstructed and the horizontal transfer of genes was predicted, indicating that the adaptation of P. aggregans to a changing marine environment depends on the evolution of their metabolic capabilities, especially in signal transmission. In conclusion, the results of this study provide genomic information for revealing the adaptive mechanism of strain HW001T to the changing ancient oceans. Supplementary Information The online version contains supplementary material available at 10.1007/s42995-023-00164-3.
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Affiliation(s)
- Shuangfei Zhang
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458 China
- Biology Department, College of Science, and Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou, 515063 China
| | - Russell T. Hill
- Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science, Baltimore, MD 21201 USA
| | - Hui Wang
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458 China
- Biology Department, College of Science, and Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou, 515063 China
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Bianco CM, Moustafa AM, O’Brien K, Martin MA, Read TD, Kreiswirth BN, Planet PJ. Pre-epidemic evolution of the MRSA USA300 clade and a molecular key for classification. Front Cell Infect Microbiol 2023; 13:1081070. [PMID: 36761897 PMCID: PMC9902376 DOI: 10.3389/fcimb.2023.1081070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 01/04/2023] [Indexed: 01/26/2023] Open
Abstract
Introduction USA300 has remained the dominant community and healthcare associated methicillin-resistant Staphylococcus aureus (MRSA) clone in the United States and in northern South America for at least the past 20 years. In this time, it has experienced epidemic spread in both of these locations. However, its pre-epidemic evolutionary history and origins are incompletely understood. Large sequencing databases, such as NCBI, PATRIC, and Staphopia, contain clues to the early evolution of USA300 in the form of sequenced genomes of USA300 isolates that are representative of lineages that diverged prior to the establishment of the South American epidemic (SAE) clade and North American epidemic (NAE) clade. In addition, historical isolates collected prior to the emergence of epidemics can help reconstruct early events in the history of this lineage. Methods Here, we take advantage of the accrued, publicly available data, as well as two newly sequenced pre-epidemic historical isolates from 1996, and a very early diverging ACME-negative NAE genome, to understand the pre-epidemic evolution of USA300. We use database mining techniques to emphasize genomes similar to pre-epidemic isolates, with the goal of reconstructing the early molecular evolution of the USA300 lineage. Results Phylogenetic analysis with these genomes confirms that the NAE and SAE USA300 lineages diverged from a most recent common ancestor around 1970 with high confidence, and it also pinpoints the independent acquisition events of the of the ACME and COMER loci with greater precision than in previous studies. We provide evidence for a North American origin of the USA300 lineage and identify multiple introductions of USA300 into South and North America. Notably, we describe a third major USA300 clade (the pre-epidemic branching clade; PEB1) consisting of both MSSA and MRSA isolates circulating around the world that diverged from the USA300 lineage prior to the establishment of the South and North American epidemics. We present a detailed analysis of specific sequence characteristics of each of the major clades, and present diagnostic positions that can be used to classify new genomes.
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Affiliation(s)
- Colleen M. Bianco
- Division of Pediatric Infectious Diseases, Children’s Hospital of Philadelphia, Philadelphia, PA, United States
| | - Ahmed M. Moustafa
- Division of Pediatric Infectious Diseases, Children’s Hospital of Philadelphia, Philadelphia, PA, United States,Division of Gastroenterology, Hepatology, and Nutrition, Children’s Hospital of Philadelphia, Philadelphia, PA, United States
| | - Kelsey O’Brien
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Michael A. Martin
- Division of Infectious Diseases & Department of Human Genetics Emory University School of Medicine, Atlanta, GA, United States
| | - Timothy D. Read
- Division of Infectious Diseases & Department of Human Genetics Emory University School of Medicine, Atlanta, GA, United States
| | - Barry N. Kreiswirth
- Center for Discovery & Innovation, Hackensack Meridian Health, Nutley, NJ, United States
| | - Paul J. Planet
- Division of Pediatric Infectious Diseases, Children’s Hospital of Philadelphia, Philadelphia, PA, United States,Department of Pediatrics, Perelman College of Medicine, University of Pennsylvania, Philadelphia, PA, United States,American Museum of Natural History, New York, NY, United States,*Correspondence: Paul J. Planet,
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Hu W, Tong Y, Liu J, Chen P, Yang H, Feng S. Improving acid resistance of Escherichia coli base on the CfaS-mediated membrane engineering strategy derived from extreme acidophile. Front Bioeng Biotechnol 2023; 11:1158931. [PMID: 37025359 PMCID: PMC10070827 DOI: 10.3389/fbioe.2023.1158931] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Accepted: 03/08/2023] [Indexed: 04/08/2023] Open
Abstract
Industrial microorganisms used for the production of organic acids often face challenges such as inhibited cell growth and reduced production efficiency due to the accumulation of acidic metabolites. One promising way for improving the acid resistance of microbial cells is to reconstruct their membranes. Herein, the overexpression of cfa2 from extreme acidophile endowed E. coli with high-performance on resistance to the acid stress. The engineered strain M1-93-Accfa2, constructed by CRISPR/Cas9-mediated chromosome integration, also exhibited a significantly higher resistance to severe acid stress. The analysis of fatty acid profiles indicated that the proportion of Cy-19:0 in the cell membrane of M1-93-Accfa2 increased by 5.26 times compared with the control, while the proportion of C18:1w9c decreased by 5.81 times. Correspondingly, the permeability and fluidity of the membrane decreased significantly. HPLC analysis demonstrated that the contents of intracellular glutamic acid, arginine, methionine and aspartic acid of M1-93-Accfa2 were 2.59, 2.04, 22.07 and 2.65 times that of the control after environmental acidification, respectively. Meanwhile, transmission electron microscopy observation indicated that M1-93-Accfa2 could maintain a plumper cell morphology after acid stimulation. M1-93-Accfa2 also exhibited higher-performance on the resistance to organic acids, especially succinic acid stress. These results together demonstrated the great potential of M1-93-Accfa2 constructed here in the production of organic acids.
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Affiliation(s)
- Wenbo Hu
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Yanjun Tong
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China
| | - Junjie Liu
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Panyan Chen
- Key Laboratory of Carbohydrate Chemistry and Biotechnology (Jiangnan University) Ministry of Education, Jiangnan University, Wuxi, China
| | - Hailin Yang
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
- Key Laboratory of Carbohydrate Chemistry and Biotechnology (Jiangnan University) Ministry of Education, Jiangnan University, Wuxi, China
- *Correspondence: Hailin Yang, ; Shoushuai Feng,
| | - Shoushuai Feng
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
- Key Laboratory of Carbohydrate Chemistry and Biotechnology (Jiangnan University) Ministry of Education, Jiangnan University, Wuxi, China
- *Correspondence: Hailin Yang, ; Shoushuai Feng,
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The Antibacterial Type VII Secretion System of Bacillus subtilis: Structure and Interactions of the Pseudokinase YukC/EssB. mBio 2022; 13:e0013422. [PMID: 36154281 PMCID: PMC9600267 DOI: 10.1128/mbio.00134-22] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Type VIIb secretion systems (T7SSb) were recently proposed to mediate different aspects of Firmicutes physiology, including bacterial pathogenicity and competition. However, their architecture and mechanism of action remain largely obscure. Here, we present a detailed analysis of the T7SSb-mediated bacterial competition in Bacillus subtilis, using the effector YxiD as a model for the LXG secreted toxins. By systematically investigating protein-protein interactions, we reveal that the membrane subunit YukC contacts all T7SSb components, including the WXG100 substrate YukE and the LXG effector YxiD. YukC’s crystal structure shows unique features, suggesting an intrinsic flexibility that is required for T7SSb antibacterial activity. Overall, our results shed light on the role and molecular organization of the T7SSb and demonstrate the potential of B. subtilis as a model system for extensive structure-function studies of these secretion machineries.
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Craven SJ, Condon SGF, Díaz Vázquez G, Cui Q, Senes A. The coiled-coil domain of Escherichia coli FtsLB is a structurally detuned element critical for modulating its activation in bacterial cell division. J Biol Chem 2022; 298:101460. [PMID: 34871549 PMCID: PMC8749076 DOI: 10.1016/j.jbc.2021.101460] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 11/24/2021] [Accepted: 11/25/2021] [Indexed: 12/24/2022] Open
Abstract
The FtsLB complex is a key regulator of bacterial cell division, existing in either an off state or an on state, which supports the activation of septal peptidoglycan synthesis. In Escherichia coli, residues known to be critical for this activation are located in a region near the C-terminal end of the periplasmic coiled-coil domain of FtsLB, raising questions about the precise role of this conserved domain in the activation mechanism. Here, we investigate an unusual cluster of polar amino acids found within the core of the FtsLB coiled coil. We hypothesized that these amino acids likely reduce the structural stability of the domain and thus may be important for governing conformational changes. We found that mutating these positions to hydrophobic residues increased the thermal stability of FtsLB but caused cell division defects, suggesting that the coiled-coil domain is a "detuned" structural element. In addition, we identified suppressor mutations within the polar cluster, indicating that the precise identity of the polar amino acids is important for fine-tuning the structural balance between the off and on states. We propose a revised structural model of the tetrameric FtsLB (named the "Y-model") in which the periplasmic domain splits into a pair of coiled-coil branches. In this configuration, the hydrophilic terminal moieties of the polar amino acids remain more favorably exposed to water than in the original four-helix bundle model ("I-model"). We propose that a shift in this architecture, dependent on its marginal stability, is involved in activating the FtsLB complex and triggering septal cell wall reconstruction.
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Affiliation(s)
- Samuel J Craven
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA; Integrated Program in Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Samson G F Condon
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA; Integrated Program in Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Gladys Díaz Vázquez
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA; Biophysics Graduate Program, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Qiang Cui
- Department of Chemistry, Boston University, Boston, Massachusetts, USA
| | - Alessandro Senes
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA.
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Bleul L, Francois P, Wolz C. Two-Component Systems of S. aureus: Signaling and Sensing Mechanisms. Genes (Basel) 2021; 13:34. [PMID: 35052374 PMCID: PMC8774646 DOI: 10.3390/genes13010034] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Revised: 12/21/2021] [Accepted: 12/22/2021] [Indexed: 12/18/2022] Open
Abstract
Staphylococcus aureus encodes 16 two-component systems (TCSs) that enable the bacteria to sense and respond to changing environmental conditions. Considering the function of these TCSs in bacterial survival and their potential role as drug targets, it is important to understand the exact mechanisms underlying signal perception. The differences between the sensing of appropriate signals and the transcriptional activation of the TCS system are often not well described, and the signaling mechanisms are only partially understood. Here, we review present insights into which signals are sensed by histidine kinases in S. aureus to promote appropriate gene expression in response to diverse environmental challenges.
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Affiliation(s)
- Lisa Bleul
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, 72076 Tubingen, Germany;
- Cluster of Excellence EXC 2124 “Controlling Microbes to Fight Infections”, University of Tübingen, Elfriede-Aulhorn-Str. 6, 72076 Tubingen, Germany
| | - Patrice Francois
- Genomic Research Laboratory, Infectious Diseases Service, University Hospitals of Geneva University Medical Center, Michel Servet 1, CH-1211 Geneva, Switzerland;
| | - Christiane Wolz
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, 72076 Tubingen, Germany;
- Cluster of Excellence EXC 2124 “Controlling Microbes to Fight Infections”, University of Tübingen, Elfriede-Aulhorn-Str. 6, 72076 Tubingen, Germany
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Mensa B, Polizzi NF, Molnar KS, Natale AM, Lemmin T, DeGrado WF. Allosteric mechanism of signal transduction in the two-component system histidine kinase PhoQ. eLife 2021; 10:73336. [PMID: 34904568 PMCID: PMC8719878 DOI: 10.7554/elife.73336] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 12/13/2021] [Indexed: 12/05/2022] Open
Abstract
Transmembrane signaling proteins couple extracytosolic sensors to cytosolic effectors. Here, we examine how binding of Mg2+ to the sensor domain of an E. coli two component histidine kinase (HK), PhoQ, modulates its cytoplasmic kinase domain. We use cysteine-crosslinking and reporter-gene assays to simultaneously and independently probe the signaling state of PhoQ’s sensor and autokinase domains in a set of over 30 mutants. Strikingly, conservative single-site mutations distant from the sensor or catalytic site strongly influence PhoQ’s ligand-sensitivity as well as the magnitude and direction of the signal. Data from 35 mutants are explained by a semi-empirical three-domain model in which the sensor, intervening HAMP, and catalytic domains can adopt kinase-promoting or inhibiting conformations that are in allosteric communication. The catalytic and sensor domains intrinsically favor a constitutively ‘kinase-on’ conformation, while the HAMP domain favors the ‘off’ state; when coupled, they create a bistable system responsive to physiological concentrations of Mg2+. Mutations alter signaling by locally modulating domain intrinsic equilibrium constants and interdomain couplings. Our model suggests signals transmit via interdomain allostery rather than propagation of a single concerted conformational change, explaining the diversity of signaling structural transitions observed in individual HK domains.
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Affiliation(s)
- Bruk Mensa
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, United States.,Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States.,Chemistry and Chemical Biology PhD program, University of California, San Francisco, San Francisco, United States
| | - Nicholas F Polizzi
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, United States
| | | | - Andrew M Natale
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, United States.,Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States.,Biophysics PhD program, University of California, San Francisco, San Francisco, United States
| | - Thomas Lemmin
- Euler Institute, Università della Svizzera Italiana, Lugano, Switzerland
| | - William F DeGrado
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, United States.,Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States
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12
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Jensen BC, Vaney P, Flaspohler J, Coppens I, Parsons M. Unusual features and localization of the membrane kinome of Trypanosoma brucei. PLoS One 2021; 16:e0258814. [PMID: 34653230 PMCID: PMC8519429 DOI: 10.1371/journal.pone.0258814] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 10/05/2021] [Indexed: 11/23/2022] Open
Abstract
In many eukaryotes, multiple protein kinases are situated in the plasma membrane where they respond to extracellular ligands. Ligand binding elicits a signal that is transmitted across the membrane, leading to activation of the cytosolic kinase domain. Humans have over 100 receptor protein kinases. In contrast, our search of the Trypanosoma brucei kinome showed that there were only ten protein kinases with predicted transmembrane domains, and unlike other eukaryotic transmembrane kinases, seven are predicted to bear multiple transmembrane domains. Most of the ten kinases, including their transmembrane domains, are conserved in both Trypanosoma cruzi and Leishmania species. Several possess accessory domains, such as Kelch, nucleotide cyclase, and forkhead-associated domains. Surprisingly, two contain multiple regions with predicted structural similarity to domains in bacterial signaling proteins. A few of the protein kinases have previously been localized to subcellular structures such as endosomes or lipid bodies. We examined the localization of epitope-tagged versions of seven of the predicted transmembrane kinases in T. brucei bloodstream forms and show that five localized to the endoplasmic reticulum. The last two kinases are enzymatically active, integral membrane proteins associated with the flagellum, flagellar pocket, or adjacent structures as shown by both fluorescence and immunoelectron microscopy. Thus, these kinases are positioned in structures suggesting participation in signal transduction from the external environment.
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Affiliation(s)
- Bryan C. Jensen
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, Washington, United States of America
- * E-mail:
| | - Pashmi Vaney
- Seattle Biomedical Research Institute, Seattle, Washington, United States of America
| | - John Flaspohler
- Biology Department, Concordia College, Moorhead, Minnesota, United States of America
| | - Isabelle Coppens
- Department of Molecular Microbiology and Immunology, Johns Hopkins School of Public Health, Baltimore, Maryland, United States of America
| | - Marilyn Parsons
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, Washington, United States of America
- Departments of Pediatrics and Global Health, University of Washington, Seattle, Washington, United States of America
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13
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Ma P, Phillips-Jones MK. Membrane Sensor Histidine Kinases: Insights from Structural, Ligand and Inhibitor Studies of Full-Length Proteins and Signalling Domains for Antibiotic Discovery. Molecules 2021; 26:molecules26165110. [PMID: 34443697 PMCID: PMC8399564 DOI: 10.3390/molecules26165110] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 08/02/2021] [Accepted: 08/19/2021] [Indexed: 12/19/2022] Open
Abstract
There is an urgent need to find new antibacterial agents to combat bacterial infections, including agents that inhibit novel, hitherto unexploited targets in bacterial cells. Amongst novel targets are two-component signal transduction systems (TCSs) which are the main mechanism by which bacteria sense and respond to environmental changes. TCSs typically comprise a membrane-embedded sensory protein (the sensor histidine kinase, SHK) and a partner response regulator protein. Amongst promising targets within SHKs are those involved in environmental signal detection (useful for targeting specific SHKs) and the common themes of signal transmission across the membrane and propagation to catalytic domains (for targeting multiple SHKs). However, the nature of environmental signals for the vast majority of SHKs is still lacking, and there is a paucity of structural information based on full-length membrane-bound SHKs with and without ligand. Reasons for this lack of knowledge lie in the technical challenges associated with investigations of these relatively hydrophobic membrane proteins and the inherent flexibility of these multidomain proteins that reduces the chances of successful crystallisation for structural determination by X-ray crystallography. However, in recent years there has been an explosion of information published on (a) methodology for producing active forms of full-length detergent-, liposome- and nanodisc-solubilised membrane SHKs and their use in structural studies and identification of signalling ligands and inhibitors; and (b) mechanisms of signal sensing and transduction across the membrane obtained using sensory and transmembrane domains in isolation, which reveal some commonalities as well as unique features. Here we review the most recent advances in these areas and highlight those of potential use in future strategies for antibiotic discovery. This Review is part of a Special Issue entitled “Interactions of Bacterial Molecules with Their Ligands and Other Chemical Agents” edited by Mary K. Phillips-Jones.
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Affiliation(s)
- Pikyee Ma
- Laboratory of Biomolecular Research, Paul Scherrer Institute, CH-5232 Villigen, Switzerland;
| | - Mary K. Phillips-Jones
- National Centre for Macromolecular Hydrodynamics, School of Biosciences, University of Nottingham, Sutton Bonington LE12 5RD, UK
- Correspondence:
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14
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Willdigg JR, Helmann JD. Mini Review: Bacterial Membrane Composition and Its Modulation in Response to Stress. Front Mol Biosci 2021; 8:634438. [PMID: 34046426 PMCID: PMC8144471 DOI: 10.3389/fmolb.2021.634438] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 04/13/2021] [Indexed: 11/13/2022] Open
Abstract
Antibiotics and other agents that perturb the synthesis or integrity of the bacterial cell envelope trigger compensatory stress responses. Focusing on Bacillus subtilis as a model system, this mini-review summarizes current views of membrane structure and insights into how cell envelope stress responses remodel and protect the membrane. Altering the composition and properties of the membrane and its associated proteome can protect cells against detergents, antimicrobial peptides, and pore-forming compounds while also, indirectly, contributing to resistance against compounds that affect cell wall synthesis. Many of these regulatory responses are broadly conserved, even where the details of regulation may differ, and can be important in the emergence of antibiotic resistance in clinical settings.
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Affiliation(s)
| | - John D. Helmann
- Department of Microbiology, Cornell University, Ithaca, NY, United States
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15
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Sensor Domain of Histidine Kinase VxrA of Vibrio cholerae- A Hairpin-swapped Dimer and its Conformational Change. J Bacteriol 2021; 203:JB.00643-20. [PMID: 33753465 PMCID: PMC8117521 DOI: 10.1128/jb.00643-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
VxrA and VxrB are cognate histidine kinase (HK) - response regulator (RR) pairs of a two-component signaling system (TCS) found in Vibrio cholerae, a bacterial pathogen that causes cholera. The VxrAB TCS positively regulates virulence, the Type VI Secretion System, biofilm formation, and cell wall homeostasis in V. cholerae, providing protection from environmental stresses and contributing to the transmission and virulence of the pathogen. The VxrA HK has a unique periplasmic sensor domain (SD) and, remarkably, lacks a cytoplasmic linker domain between the second transmembrane helix and the dimerization and histidine phosphotransfer (DHp) domain, indicating that this system may utilize a potentially unique signal sensing and transmission TCS mechanism. In this study, we have determined several crystal structures of VxrA-SD and its mutants. These structures reveal a novel structural fold forming an unusual β hairpin-swapped dimer. A conformational change caused by relative rotation of the two monomers in a VxrA-SD dimer could potentially change the association of transmembrane helices and, subsequently, the pairing of cytoplasmic DHp domains. Based on the structural observation, we propose a putative scissor-like closing regulation mechanism for the VxrA HK.IMPORTANCE V. cholerae has a dynamic life cycle, which requires rapid adaptation to changing external conditions. Two-component signal transduction (TCS) systems allow V. cholerae to sense and respond to these environmental changes. The VxrAB TCS positively regulates a number of important V. cholerae phenotypes, including virulence, the Type Six Secretion System, biofilm formation, and cell wall homeostasis. Here, we provide the crystal structure of the VxrA sensor histidine kinase sensing domain and propose a mechanism for signal transduction. The cognate signal for VxrAB remains unknown, however, in this work we couple our structural analysis with functional assessments of key residues to further our understanding of this important TCS.
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16
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Willdigg JR, Helmann JD. Mini Review: Bacterial Membrane Composition and Its Modulation in Response to Stress. Front Mol Biosci 2021. [PMID: 34046426 DOI: 10.3389/fmolb.2021.634438/bibtex] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/23/2023] Open
Abstract
Antibiotics and other agents that perturb the synthesis or integrity of the bacterial cell envelope trigger compensatory stress responses. Focusing on Bacillus subtilis as a model system, this mini-review summarizes current views of membrane structure and insights into how cell envelope stress responses remodel and protect the membrane. Altering the composition and properties of the membrane and its associated proteome can protect cells against detergents, antimicrobial peptides, and pore-forming compounds while also, indirectly, contributing to resistance against compounds that affect cell wall synthesis. Many of these regulatory responses are broadly conserved, even where the details of regulation may differ, and can be important in the emergence of antibiotic resistance in clinical settings.
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Affiliation(s)
- Jessica R Willdigg
- Department of Microbiology, Cornell University, Ithaca, NY, United States
| | - John D Helmann
- Department of Microbiology, Cornell University, Ithaca, NY, United States
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17
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Gushchin I, Orekhov P, Melnikov I, Polovinkin V, Yuzhakova A, Gordeliy V. Sensor Histidine Kinase NarQ Activates via Helical Rotation, Diagonal Scissoring, and Eventually Piston-Like Shifts. Int J Mol Sci 2020; 21:E3110. [PMID: 32354084 PMCID: PMC7247690 DOI: 10.3390/ijms21093110] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 04/19/2020] [Accepted: 04/24/2020] [Indexed: 12/20/2022] Open
Abstract
Membrane-embedded sensor histidine kinases (HKs) and chemoreceptors are used ubiquitously by bacteria and archaea to percept the environment, and are often crucial for their survival and pathogenicity. The proteins can transmit the signal from the sensor domain to the catalytic kinase domain reliably over the span of several hundreds of angstroms, and regulate the activity of the cognate response regulator proteins, with which they form two-component signaling systems (TCSs). Several mechanisms of transmembrane signal transduction in TCS receptors have been proposed, dubbed (swinging) piston, helical rotation, and diagonal scissoring. Yet, despite decades of studies, there is no consensus on whether these mechanisms are common for all TCS receptors. Here, we extend our previous work on Escherichia coli nitrate/nitrite sensor kinase NarQ. We determined a crystallographic structure of the sensor-TM-HAMP fragment of the R50S mutant, which, unexpectedly, was found in a ligand-bound-like conformation, despite an inability to bind nitrate. Subsequently, we reanalyzed the structures of the ligand-free and ligand-bound NarQ and NarX sensor domains, and conducted extensive molecular dynamics simulations of ligand-free and ligand-bound wild type and mutated NarQ. Based on the data, we show that binding of nitrate to NarQ causes, first and foremost, helical rotation and diagonal scissoring of the α-helices at the core of the sensor domain. These conformational changes are accompanied by a subtle piston-like motion, which is amplified by a switch in the secondary structure of the linker between the sensor and TM domains. We conclude that helical rotation, diagonal scissoring, and piston are simply different degrees of freedom in coiled-coil proteins and are not mutually exclusive in NarQ, and likely in other nitrate sensors and TCS proteins as well.
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Affiliation(s)
- Ivan Gushchin
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Russia
| | - Philipp Orekhov
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Russia
- Institute of Personalized Medicine, Sechenov University, 119146 Moscow, Russia
| | - Igor Melnikov
- Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich, 52428 Jülich, Germany
- European Synchrotron Radiation Facility, 38000 Grenoble, France
| | - Vitaly Polovinkin
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Russia
- Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich, 52428 Jülich, Germany
- Institut de Biologie Structurale J.-P. Ebel, Université Grenoble Alpes-CEA-CNRS, 38000 Grenoble, France
| | - Anastasia Yuzhakova
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Russia
- Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich, 52428 Jülich, Germany
| | - Valentin Gordeliy
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Russia
- Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich, 52428 Jülich, Germany
- Institut de Biologie Structurale J.-P. Ebel, Université Grenoble Alpes-CEA-CNRS, 38000 Grenoble, France
- JuStruct: Jülich Center for Structural Biology, Forschungszentrum Jülich, 52428 Jülich, Germany
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18
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Yang Y, Lang N, Zhang L, Wu H, Jiang W, Gu Y. A novel regulatory pathway consisting of a two-component system and an ABC-type transporter contributes to butanol tolerance in Clostridium acetobutylicum. Appl Microbiol Biotechnol 2020; 104:5011-5023. [DOI: 10.1007/s00253-020-10555-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 02/23/2020] [Accepted: 03/16/2020] [Indexed: 11/28/2022]
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