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Torres-Sánchez L, Sana TG, Decossas M, Hashem Y, Krasteva PV. Structures of the P. aeruginosa FleQ-FleN master regulators reveal large-scale conformational switching in motility and biofilm control. Proc Natl Acad Sci U S A 2023; 120:e2312276120. [PMID: 38051770 PMCID: PMC10723142 DOI: 10.1073/pnas.2312276120] [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: 07/21/2023] [Accepted: 11/01/2023] [Indexed: 12/07/2023] Open
Abstract
Pseudomonas aeruginosa can cause a wide array of chronic and acute infections associated with its ability to rapidly switch between planktonic, biofilm, and dispersed lifestyles, each with a specific arsenal for bacterial survival and virulence. At the cellular level, many of the physiological transitions are orchestrated by the intracellular second messenger c-di-GMP and its receptor-effector FleQ. A bacterial enhancer binding protein, FleQ acts as a master regulator of both flagellar motility and adherence factor secretion and uses remarkably different transcription activation mechanisms depending on its dinucleotide loading state, adenosine triphosphatase (ATPase) activity, interactions with polymerase sigma (σ) factors, and complexation with a second ATPase, FleN. How the FleQ-FleN tandem can exert diverse effects through recognition of a conserved FleQ binding consensus has remained enigmatic. Here, we provide cryogenic electron microscopy (cryo-EM) structures of both c-di-GMP-bound and c-di-GMP-free FleQ-FleN complexes which deepen our understanding of the proteins' (di)nucleotide-dependent conformational switching and fine-tuned roles in gene expression regulation.
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Affiliation(s)
- Lucía Torres-Sánchez
- Université de Bordeaux, CNRS, Bordeaux INP, CBMN, UMR 5248, PessacF-33600, France
- Structural Biology of Biofilms Group, European Institute of Chemistry and Biology, PessacF-33600, France
- Doctoral School of Therapeutic Innovation (ITFA), Université Paris-Saclay, Gif-sur-YvetteF-91190, France
| | - Thibault Géry Sana
- Université de Bordeaux, CNRS, Bordeaux INP, CBMN, UMR 5248, PessacF-33600, France
- Structural Biology of Biofilms Group, European Institute of Chemistry and Biology, PessacF-33600, France
| | - Marion Decossas
- Université de Bordeaux, CNRS, Bordeaux INP, CBMN, UMR 5248, PessacF-33600, France
- Structural Biology of Biofilms Group, European Institute of Chemistry and Biology, PessacF-33600, France
| | - Yaser Hashem
- ARNA Laboratory, European Institute of Chemistry and Biology, U1212 INSERM, UMR5320 CNRS, Université de Bordeaux, PessacF-33600, France
| | - Petya Violinova Krasteva
- Université de Bordeaux, CNRS, Bordeaux INP, CBMN, UMR 5248, PessacF-33600, France
- Structural Biology of Biofilms Group, European Institute of Chemistry and Biology, PessacF-33600, France
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Wu S, Tang J, Wang B, Cai J, Jian J. Roles of Hcp2, a Hallmark of T6SS2 in Motility, Adhesive Capacity, and Pathogenicity of Vibrio alginolyticus. Microorganisms 2023; 11:2893. [PMID: 38138037 PMCID: PMC10745990 DOI: 10.3390/microorganisms11122893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 11/28/2023] [Accepted: 11/29/2023] [Indexed: 12/24/2023] Open
Abstract
The type VI secretion system (T6SS) is a large secretory device, widely found in Gram-negative bacteria, which plays important roles in virulence, bacterial competition, and environmental adaptation. Vibrio alginolyticus (V. alginolyticus) is an opportunistic pathogen that causes vibriosis in aquaculture animals. V. alginolyticus possesses two type VI secretion systems (named the T6SS1 and T6SS2), but their functions remain largely unclear. In this paper, the roles of the core component of the T6SS2 cluster of V. alginolyticus HY9901, hemolysin-coregulated protein2 coding gene hcp2, are reported. Deletion of hcp2 clearly impaired the swarming motility, adhesive capacity, and pathogenicity of V. alginolyticus against zebrafish. Furthermore, transmission electron microscopy (TEM) found that the abnormal morphology of flagellum filament in the hcp2 mutant strain could be partially restored by hcp2 complementarity. By proteomic and RT-qPCR analysis, we confirmed that the expression levels of flagellar flagellin and assembly-associated proteins were remarkably decreased in an hcp2 mutant strain, compared with the wild-type strain, and could be partially restored with a supply of hcp2. Accordingly, hcp2 had a positive influence on the transcription of flagellar regulons rpoN, rpoS, and fliA; this was verified by RT-qPCR. Taken together, these results suggested that hcp2 was involved in mediating the motility, adhesion, and pathogenicity of Vibrio alginolyticus through positively impacting its flagellar system.
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Affiliation(s)
- Shuilong Wu
- Guangdong Provincial Key Laboratory of Aquatic Animal Disease Control and Healthy Culture, College of Fishery, Guangdong Ocean University, Zhanjiang 524088, China
- Key Laboratory of Diseases Controlling for Aquatic Economic Animals of Guangdong Higher Education Institutions, College of Fishery, Guangdong Ocean University, Zhanjiang 524088, China
- Central People’s Hospital of Zhanjiang, Zhanjiang 524045, China
| | - Jufen Tang
- Guangdong Provincial Key Laboratory of Aquatic Animal Disease Control and Healthy Culture, College of Fishery, Guangdong Ocean University, Zhanjiang 524088, China
- Key Laboratory of Diseases Controlling for Aquatic Economic Animals of Guangdong Higher Education Institutions, College of Fishery, Guangdong Ocean University, Zhanjiang 524088, China
| | - Bei Wang
- Guangdong Provincial Key Laboratory of Aquatic Animal Disease Control and Healthy Culture, College of Fishery, Guangdong Ocean University, Zhanjiang 524088, China
- Key Laboratory of Diseases Controlling for Aquatic Economic Animals of Guangdong Higher Education Institutions, College of Fishery, Guangdong Ocean University, Zhanjiang 524088, China
| | - Jia Cai
- Guangdong Provincial Key Laboratory of Aquatic Animal Disease Control and Healthy Culture, College of Fishery, Guangdong Ocean University, Zhanjiang 524088, China
- Key Laboratory of Diseases Controlling for Aquatic Economic Animals of Guangdong Higher Education Institutions, College of Fishery, Guangdong Ocean University, Zhanjiang 524088, China
| | - Jichang Jian
- Guangdong Provincial Key Laboratory of Aquatic Animal Disease Control and Healthy Culture, College of Fishery, Guangdong Ocean University, Zhanjiang 524088, China
- Key Laboratory of Diseases Controlling for Aquatic Economic Animals of Guangdong Higher Education Institutions, College of Fishery, Guangdong Ocean University, Zhanjiang 524088, China
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