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Tan J, Zhang L, Zhou X, Han S, Zhou Y, Zhu Y. Structural basis of the bacterial flagellar motor rotational switching. Cell Res 2024:10.1038/s41422-024-01017-z. [PMID: 39179739 DOI: 10.1038/s41422-024-01017-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2024] [Accepted: 08/08/2024] [Indexed: 08/26/2024] Open
Abstract
The bacterial flagellar motor is a huge bidirectional rotary nanomachine that drives rotation of the flagellum for bacterial motility. The cytoplasmic C ring of the flagellar motor functions as the switch complex for the rotational direction switching from counterclockwise to clockwise. However, the structural basis of the rotational switching and how the C ring is assembled have long remained elusive. Here, we present two high-resolution cryo-electron microscopy structures of the C ring-containing flagellar basal body-hook complex from Salmonella Typhimurium, which are in the default counterclockwise state and in a constitutively active CheY mutant-induced clockwise state, respectively. In both complexes, the C ring consists of four subrings, but is in two different conformations. The CheY proteins are bound into an open groove between two adjacent protomers on the surface of the middle subring of the C ring and interact with the FliG and FliM subunits. The binding of the CheY protein induces a significant upward shift of the C ring towards the MS ring and inward movements of its protomers towards the motor center, which eventually remodels the structures of the FliG subunits and reverses the orientations and surface electrostatic potential of the αtorque helices to trigger the counterclockwise-to-clockwise rotational switching. The conformational changes of the FliG subunits reveal that the stator units on the motor require a relocation process in the inner membrane during the rotational switching. This study provides unprecedented molecular insights into the rotational switching mechanism and a detailed overall structural view of the bacterial flagellar motors.
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Affiliation(s)
- Jiaxing Tan
- Department of Gastroenterology of the Second Affiliated Hospital, School of Medicine and College of Animal Sciences, Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang, China
- The MOE Key Laboratory of Biosystems Homeostasis & Protection, and Zhejiang Provincial Key Laboratory of Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang, China
| | - Ling Zhang
- Department of Gastroenterology of the Second Affiliated Hospital, School of Medicine and College of Animal Sciences, Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang, China
- The MOE Key Laboratory of Biosystems Homeostasis & Protection, and Zhejiang Provincial Key Laboratory of Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang, China
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Xingtong Zhou
- Department of Gastroenterology of the Second Affiliated Hospital, School of Medicine and College of Animal Sciences, Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang, China
- The MOE Key Laboratory of Biosystems Homeostasis & Protection, and Zhejiang Provincial Key Laboratory of Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang, China
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Siyu Han
- Department of Gastroenterology of the Second Affiliated Hospital, School of Medicine and College of Animal Sciences, Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang, China
- The MOE Key Laboratory of Biosystems Homeostasis & Protection, and Zhejiang Provincial Key Laboratory of Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang, China
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Yan Zhou
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China.
| | - Yongqun Zhu
- Department of Gastroenterology of the Second Affiliated Hospital, School of Medicine and College of Animal Sciences, Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang, China.
- The MOE Key Laboratory of Biosystems Homeostasis & Protection, and Zhejiang Provincial Key Laboratory of Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang, China.
- Shanghai Institute for Advanced Study, Zhejiang University, Shanghai, China.
- Cancer Center, Zhejiang University, Hangzhou, Zhejiang, China.
- Center for Veterinary Sciences, Department of Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang, China.
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Wang X, Blumenfeld R, Feng XQ, Weitz DA. 'Phase transitions' in bacteria - From structural transitions in free living bacteria to phenotypic transitions in bacteria within biofilms. Phys Life Rev 2022; 43:98-138. [PMID: 36252408 DOI: 10.1016/j.plrev.2022.09.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Accepted: 09/30/2022] [Indexed: 12/05/2022]
Abstract
Phase transitions are common in inanimate systems and have been studied extensively in natural sciences. Less explored are the rich transitions that take place at the micro- and nano-scales in biological systems. In conventional phase transitions, large-scale properties of the media change discontinuously in response to continuous changes in external conditions. Such changes play a significant role in the dynamic behaviours of organisms. In this review, we focus on some transitions in both free-living and biofilms of bacteria. Particular attention is paid to the transitions in the flagellar motors and filaments of free-living bacteria, in cellular gene expression during the biofilm growth, in the biofilm morphology transitions during biofilm expansion, and in the cell motion pattern transitions during the biofilm formation. We analyse the dynamic characteristics and biophysical mechanisms of these phase transition phenomena and point out the parallels between these transitions and conventional phase transitions. We also discuss the applications of some theoretical and numerical methods, established for conventional phase transitions in inanimate systems, in bacterial biofilms.
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Affiliation(s)
- Xiaoling Wang
- School of Mechanical Engineering, University of Science and Technology Beijing, Beijing 100083, China; John A. Paulson School of Engineering and Applied Sciences, Harvard University, 9 Oxford St, Cambridge, MA, 02138, USA.
| | - Raphael Blumenfeld
- Gonville & Caius College, University of Cambridge, Trinity St., Cambridge CB2 1TA, UK
| | - Xi-Qiao Feng
- Institute of Biomechanics and Medical Engineering, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
| | - David A Weitz
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, 9 Oxford St, Cambridge, MA, 02138, USA; Department of Physics, Harvard University, 9 Oxford St, Cambridge, MA, 02138, USA
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Li Q. Geometric basis of action potential of skeletal muscle cells and neurons. Open Life Sci 2022; 17:1191-1199. [PMID: 36185399 PMCID: PMC9482420 DOI: 10.1515/biol-2022-0488] [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: 02/23/2022] [Revised: 07/19/2022] [Accepted: 07/28/2022] [Indexed: 11/15/2022] Open
Abstract
Although we know something about single-cell neuromuscular junctions, it is still unclear how multiple skeletal muscle cells coordinate to complete intricate spatial curve movement. Here, we hypothesize that skeletal muscle cell populations with action potentials are aligned according to curved manifolds in space (a curved shape in space). When a specific motor nerve impulse is transmitted, the skeletal muscle also moves according to the corresponding shape (manifolds). The action potential of motor nerve fibers has the characteristics of a time curve manifold, and this time-manifold curve of motor nerve fibers comes from the visual cortex in which spatial geometric manifolds are formed within the synaptic connection of neurons. This spatial geometric manifold of the synaptic connection of neurons originates from spatial geometric manifolds outside nature that are transmitted to the brain through the cone cells and ganglion cells of the retina. The essence of life is that life is an object that can move autonomously, and the essence of life's autonomous movement is the movement of proteins. Theoretically, because of the infinite diversity of geometric manifold shapes in nature, the arrangement and combination of 20 amino acids should have infinite diversity, and the geometric manifold formed by the protein three-dimensional spatial structure should also have infinite diversity.
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Affiliation(s)
- Qing Li
- Department of Function, ShiJiaZhuang Traditional Chinese Medical Hospital, No. 233, ZhongShan West Road, ShiJiaZhuang, HeBei Province 050051, China
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Yin L, Shen X, Zhang D, Zhao R, Dai Y, Hu X, Zhou X, Hou H, Pan X, Qi K. Flagellar rotor protein FliG is involved in the virulence of avian pathogenic Escherichia coli. Microb Pathog 2021; 160:105198. [PMID: 34537273 DOI: 10.1016/j.micpath.2021.105198] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 08/13/2021] [Accepted: 09/14/2021] [Indexed: 10/25/2022]
Abstract
Avian pathogenic Escherichia coli (APEC), a type of extraintestinal pathogenic E. coli, causes avian colibacillosis, a disease of significant economic importance to poultry producers worldwide, which is characterized by systemic infection. However, the pathogenesis of avian pathogenic E. coli strains is not well defined. Here, the role of a flagellar rotor protein encoded by the fliG gene of avian pathogenic E. coli strain AE17 was investigated. To study the role of FliG in the pathogenicity of APEC, fliG mutant and complemented strains were constructed and characterized. The inactivation of fliG had no effect on APEC growth, but significantly reduced bacterial motility. Compared with the wild type, the fliG mutant was highly attenuated in a chick infection model and showed severe defects in its adherence to and invasion of chicken embryo fibroblast DF-1 cells. The fliG mutant also showed reduced resistance to serum in chicks. The expression of the inflammatory cytokines interleukin 1β (IL1β), IL6, and IL8 was reduced in HD-11 macrophages infected with the fliG mutant strain compared with their expression in the wild-type strain. These results demonstrate that the FliG contributes to the virulence of APEC.
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Affiliation(s)
- Lei Yin
- Anhui Province Key Laboratory of Livestock and Poultry Product Safety Engineering, Livestock and Poultry Epidemic Diseases Research Center of Anhui Province, Institute of Animal Husbandry and Veterinary Science, Anhui Academy of Agricultural Sciences, Hefei, Anhui, 230031, China
| | - Xuehuai Shen
- Anhui Province Key Laboratory of Livestock and Poultry Product Safety Engineering, Livestock and Poultry Epidemic Diseases Research Center of Anhui Province, Institute of Animal Husbandry and Veterinary Science, Anhui Academy of Agricultural Sciences, Hefei, Anhui, 230031, China
| | - Danjun Zhang
- Anhui Province Key Laboratory of Livestock and Poultry Product Safety Engineering, Livestock and Poultry Epidemic Diseases Research Center of Anhui Province, Institute of Animal Husbandry and Veterinary Science, Anhui Academy of Agricultural Sciences, Hefei, Anhui, 230031, China
| | - Ruihong Zhao
- Anhui Province Key Laboratory of Livestock and Poultry Product Safety Engineering, Livestock and Poultry Epidemic Diseases Research Center of Anhui Province, Institute of Animal Husbandry and Veterinary Science, Anhui Academy of Agricultural Sciences, Hefei, Anhui, 230031, China
| | - Yin Dai
- Anhui Province Key Laboratory of Livestock and Poultry Product Safety Engineering, Livestock and Poultry Epidemic Diseases Research Center of Anhui Province, Institute of Animal Husbandry and Veterinary Science, Anhui Academy of Agricultural Sciences, Hefei, Anhui, 230031, China
| | - Xiaomiao Hu
- Anhui Province Key Laboratory of Livestock and Poultry Product Safety Engineering, Livestock and Poultry Epidemic Diseases Research Center of Anhui Province, Institute of Animal Husbandry and Veterinary Science, Anhui Academy of Agricultural Sciences, Hefei, Anhui, 230031, China
| | - Xueli Zhou
- Anhui Province Key Laboratory of Livestock and Poultry Product Safety Engineering, Livestock and Poultry Epidemic Diseases Research Center of Anhui Province, Institute of Animal Husbandry and Veterinary Science, Anhui Academy of Agricultural Sciences, Hefei, Anhui, 230031, China
| | - Hongyan Hou
- Anhui Province Key Laboratory of Livestock and Poultry Product Safety Engineering, Livestock and Poultry Epidemic Diseases Research Center of Anhui Province, Institute of Animal Husbandry and Veterinary Science, Anhui Academy of Agricultural Sciences, Hefei, Anhui, 230031, China
| | - Xiaocheng Pan
- Anhui Province Key Laboratory of Livestock and Poultry Product Safety Engineering, Livestock and Poultry Epidemic Diseases Research Center of Anhui Province, Institute of Animal Husbandry and Veterinary Science, Anhui Academy of Agricultural Sciences, Hefei, Anhui, 230031, China.
| | - Kezong Qi
- Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, College of Animal Science and Technology, Anhui Agricultural University, Hefei, 230036, PR China.
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Bacterial Flagellar Filament: A Supramolecular Multifunctional Nanostructure. Int J Mol Sci 2021; 22:ijms22147521. [PMID: 34299141 PMCID: PMC8306008 DOI: 10.3390/ijms22147521] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 07/06/2021] [Accepted: 07/10/2021] [Indexed: 02/07/2023] Open
Abstract
The bacterial flagellum is a complex and dynamic nanomachine that propels bacteria through liquids. It consists of a basal body, a hook, and a long filament. The flagellar filament is composed of thousands of copies of the protein flagellin (FliC) arranged helically and ending with a filament cap composed of an oligomer of the protein FliD. The overall structure of the filament core is preserved across bacterial species, while the outer domains exhibit high variability, and in some cases are even completely absent. Flagellar assembly is a complex and energetically costly process triggered by environmental stimuli and, accordingly, highly regulated on transcriptional, translational and post-translational levels. Apart from its role in locomotion, the filament is critically important in several other aspects of bacterial survival, reproduction and pathogenicity, such as adhesion to surfaces, secretion of virulence factors and formation of biofilms. Additionally, due to its ability to provoke potent immune responses, flagellins have a role as adjuvants in vaccine development. In this review, we summarize the latest knowledge on the structure of flagellins, capping proteins and filaments, as well as their regulation and role during the colonization and infection of the host.
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Recent Advances in the Bacterial Flagellar Motor Study. Biomolecules 2021; 11:biom11050741. [PMID: 34067523 PMCID: PMC8156572 DOI: 10.3390/biom11050741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 05/14/2021] [Indexed: 11/17/2022] Open
Abstract
The bacterial flagellum is a supramolecular motility machine that allows bacterial cells to swim in liquid environments [...].
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Chang Y, Carroll BL, Liu J. Structural basis of bacterial flagellar motor rotation and switching. Trends Microbiol 2021; 29:1024-1033. [PMID: 33865677 DOI: 10.1016/j.tim.2021.03.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 03/11/2021] [Accepted: 03/16/2021] [Indexed: 01/08/2023]
Abstract
The bacterial flagellar motor, a remarkable rotary machine, can rapidly switch between counterclockwise (CCW) and clockwise (CW) rotational directions to control the migration behavior of the bacterial cell. The flagellar motor consists of a bidirectional spinning rotor surrounded by torque-generating stator units. Recent high-resolution in vitro and in situ structural studies have revealed stunning details of the individual components of the flagellar motor and their interactions in both the CCW and CW senses. In this review, we discuss these structures and their implications for understanding the molecular mechanisms underlying flagellar rotation and switching.
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Affiliation(s)
- Yunjie Chang
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, CT 06536, USA; Microbial Sciences Institute, Yale University, West Haven, CT 06516, USA
| | - Brittany L Carroll
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, CT 06536, USA; Microbial Sciences Institute, Yale University, West Haven, CT 06516, USA
| | - Jun Liu
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, CT 06536, USA; Microbial Sciences Institute, Yale University, West Haven, CT 06516, USA.
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