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Dhindwal P, Boniecki MT, Moore SA. Helicobacter pylori FlgN binds its substrate FlgK and the flagellum ATPase FliI in a similar manner observed for the FliT chaperone. Protein Sci 2024; 33:e4882. [PMID: 38151822 PMCID: PMC10804663 DOI: 10.1002/pro.4882] [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: 07/28/2023] [Revised: 12/19/2023] [Accepted: 12/20/2023] [Indexed: 12/29/2023]
Abstract
In bacterial flagellum biogenesis, secretion of the hook-filament junction proteins FlgK and FlgL and completion of the flagellum requires the FlgN chaperone. Similarly, the related FliT chaperone is necessary for the secretion of the filament cap protein FliD and binds the flagellar export gate protein FlhA and the flagellum ATPase FliI. FlgN and FliT require FliJ for effective substrate secretion. In Helicobacter pylori, neither FlgN, FliT, nor FliJ have been annotated. We demonstrate that the genome location of HP1120 is identical to that of flgN in other flagellated bacteria and that HP1120 is the homolog of Campylobacter jejuni FlgN. A modeled HP1120 structure contains three α-helices and resembles the FliT chaperone, sharing a similar substrate-binding pocket. Using pulldowns and thermophoresis, we show that both HP1120 and a HP1120Δ126-144 deletion mutant bind to FlgK with nanomolar affinity, but not to the filament cap protein FliD, confirming that HP1120 is FlgN. Based on size-exclusion chromatography and multi-angle light scattering, H. pylori FlgN binds to FlgK with 1:1 stoichiometry. Overall structural similarities between FlgN and FliT suggest that substrate recognition on FlgN primarily involves an antiparallel coiled-coil interface between the third helix of FlgN and the C-terminal helix of the substrate. A FlgNΔ126-144 N100A, Y103A, S111I triple mutant targeting this interface significantly impairs the binding of FlgK. Finally, we demonstrate that FlgNΔ126-144 , like FliT, binds with sub-micromolar affinity to the flagellum ATPase FliI or its N-terminal domain. Hence FlgN and FliT likely couple delivery of low-abundance export substrates to the flagellum ATPase FliI.
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Affiliation(s)
- Poonam Dhindwal
- Department of Biochemistry, Microbiology and ImmunologyCollege of Medicine, University of SaskatchewanSaskatoonCanada
| | - Michal T. Boniecki
- Department of Biochemistry, Microbiology and ImmunologyCollege of Medicine, University of SaskatchewanSaskatoonCanada
| | - Stanley A. Moore
- Department of Biochemistry, Microbiology and ImmunologyCollege of Medicine, University of SaskatchewanSaskatoonCanada
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Fan D, Gong Y, Sun L, Zhang Y, Zhang J. Comparative transcriptome analysis to investigate the mechanism of anti-Helicobacter pylori activity of zinc. Microb Pathog 2022; 168:105611. [PMID: 35660509 DOI: 10.1016/j.micpath.2022.105611] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 03/22/2022] [Accepted: 05/28/2022] [Indexed: 10/18/2022]
Abstract
As a potential anti-Helicobacter pylori agent, zinc causes impairment of Helicobacter pylori growth, and this property of zinc is of broad interest to biological investigators. However, little is known about the molecular mechanisms by which zinc inhibits the growth of Helicobacter pylori. Here, an in vitro experiment revealed that zinc at specific concentrations inhibits Helicobacter pylori growth. Furthermore, an RNA sequencing-based investigation of the global regulatory response to zinc revealed that exposure to zinc altered the Helicobacter pylori transcriptional profile in numerous ways. A high concentration of zinc induced the upregulation of genes related to ribosomal subunit, ribosome biosynthesis, chaperone and adhesins. However, flagellar assembly genes and some type IV secretion system genes were repressed. In addition, the expression levels of some genes that encode transporters of metal ions and that play key roles in Helicobacter pylori pathogenicity were altered under conditions of zinc-induced stress. In summary, high concentrations of zinc initiated antimicrobial activity to Helicobacter pylori under the combined effect of multiple repressed or altered pathogenetic genes and metabolic pathways associated with bacteria growth. This result has significant implications for understanding not only the antimicrobial activity mechanism of zinc but also the role of zinc-mediated homeostasis in Helicobacter pylori.
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Affiliation(s)
- Dongjie Fan
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 102206, China.
| | - Yanan Gong
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 102206, China.
| | - Lu Sun
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 102206, China.
| | - Yiyao Zhang
- Healthcare Security Bureau of Haidian District, Beijing, 100000, China.
| | - Jianzhong Zhang
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 102206, China.
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Srikhanta YN, Gorrell RJ, Power PM, Tsyganov K, Boitano M, Clark TA, Korlach J, Hartland EL, Jennings MP, Kwok T. Methylomic and phenotypic analysis of the ModH5 phasevarion of Helicobacter pylori. Sci Rep 2017; 7:16140. [PMID: 29170397 PMCID: PMC5700931 DOI: 10.1038/s41598-017-15721-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Accepted: 10/31/2017] [Indexed: 12/20/2022] Open
Abstract
The Helicobacter pylori phase variable gene modH, typified by gene HP1522 in strain 26695, encodes a N6-adenosine type III DNA methyltransferase. Our previous studies identified multiple strain-specific modH variants (modH1 – modH19) and showed that phase variation of modH5 in H. pylori P12 influenced expression of motility-associated genes and outer membrane protein gene hopG. However, the ModH5 DNA recognition motif and the mechanism by which ModH5 controls gene expression were unknown. Here, using comparative single molecule real-time sequencing, we identify the DNA site methylated by ModH5 as 5′-Gm6ACC-3′. This motif is vastly underrepresented in H. pylori genomes, but overrepresented in a number of virulence genes, including motility-associated genes, and outer membrane protein genes. Motility and the number of flagella of H. pylori P12 wild-type were significantly higher than that of isogenic modH5 OFF or ΔmodH5 mutants, indicating that phase variable switching of modH5 expression plays a role in regulating H. pylori motility phenotypes. Using the flagellin A (flaA) gene as a model, we show that ModH5 modulates flaA promoter activity in a GACC methylation-dependent manner. These findings provide novel insights into the role of ModH5 in gene regulation and how it mediates epigenetic regulation of H. pylori motility.
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Affiliation(s)
- Yogitha N Srikhanta
- Department of Microbiology, Monash University, Clayton, 3800, Victoria, Australia.,Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Parkville, 3010, Victoria, Australia.,Infection and Immunity Program, Biomedicine Discovery Institute, Monash University, Clayton, 3800, Victoria, Australia
| | - Rebecca J Gorrell
- Department of Microbiology, Monash University, Clayton, 3800, Victoria, Australia.,Infection and Immunity Program, Biomedicine Discovery Institute, Monash University, Clayton, 3800, Victoria, Australia.,Department of Biochemistry and Molecular Biology, Monash University, Clayton, 3800, Victoria, Australia.,Cancer Program, Biomedicine Discovery Institute, Monash University, Clayton, 3800, Victoria, Australia
| | - Peter M Power
- Institute for Glycomics, Griffith University, Gold Coast, Queensland, 4222, Australia
| | - Kirill Tsyganov
- Bioinformatics Platform, Monash University, Clayton, 3800, Victoria, Australia
| | | | | | | | - Elizabeth L Hartland
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Parkville, 3010, Victoria, Australia.,Department of Molecular and Translational Science, Hudson Institute of Medical Research, Monash University, Clayton, 3800, Victoria, Australia
| | - Michael P Jennings
- Institute for Glycomics, Griffith University, Gold Coast, Queensland, 4222, Australia.
| | - Terry Kwok
- Department of Microbiology, Monash University, Clayton, 3800, Victoria, Australia. .,Infection and Immunity Program, Biomedicine Discovery Institute, Monash University, Clayton, 3800, Victoria, Australia. .,Department of Biochemistry and Molecular Biology, Monash University, Clayton, 3800, Victoria, Australia. .,Cancer Program, Biomedicine Discovery Institute, Monash University, Clayton, 3800, Victoria, Australia.
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Kao CY, Chen JW, Wang S, Sheu BS, Wu JJ. The Helicobacter pylori J99 jhp0106 Gene, under the Control of the CsrA/RpoN Regulatory System, Modulates Flagella Formation and Motility. Front Microbiol 2017; 8:483. [PMID: 28400753 PMCID: PMC5368276 DOI: 10.3389/fmicb.2017.00483] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 03/08/2017] [Indexed: 12/11/2022] Open
Abstract
CsrA has been shown to positively control the expression of flagella-related genes, including flaA and flaB, through regulating expression of an alternative sigma factor RpoN in Helicobacter pylori J99. Here, we aimed to characterize the CsrA regulatory system by comparative transcriptomic analysis carried out with RNA-seq on strain J99 and a csrA mutant. Fifty-three genes in the csrA mutant were found to be differentially expressed compared with the wild-type. Among CsrA-regulated genes, jhp0106, with unclear function, was found located downstream of flaB in the J99 genome. We hypothesized that flaB-jhp0106 is in an operon under the control of RpoN binding to the flaB promoter. The RT-qPCR results showed the expression of jhp0106 was decreased 76 and 92% in the csrA and rpoN mutants, respectively, compared to the wild-type. Moreover, mutations of the RpoN binding site in the flaB promoter region resulted in decreased expression of flaB and jhp0106 and deficient motility. Three-dimensional structure modeling results suggested that Jhp0106 was a glycosyltransferase. The role of jhp0106 in H. pylori was further investigated by constructing the jhp0106 mutant and revertant strains. A soft-agar motility assay and transmission electron microscope were used to determine the motility and flagellar structure of examined strains, and the results showed the loss of motility and flagellar structure in jhp0106 mutant J99. In conclusion, we found jhp0106, under the control of the CsrA/RpoN regulatory system, plays a critical role in H. pylori flagella formation.
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Affiliation(s)
- Cheng-Yen Kao
- Department of Biotechnology and Laboratory Science in Medicine, School of Biomedical Science and Engineering, National Yang Ming University Taipei, Taiwan
| | - Jenn-Wei Chen
- Center of Infectious Disease and Signaling Research, National Cheng Kung UniversityTainan, Taiwan; Department of Microbiology and Immunology, College of Medicine, National Cheng Kung UniversityTainan, Taiwan
| | - Shuying Wang
- Center of Infectious Disease and Signaling Research, National Cheng Kung UniversityTainan, Taiwan; Department of Microbiology and Immunology, College of Medicine, National Cheng Kung UniversityTainan, Taiwan
| | - Bor-Shyang Sheu
- Department of Internal Medicine, College of Medicine, National Cheng Kung University Hospital, National Cheng Kung UniversityTainan, Taiwan; Department of Internal Medicine, Tainan Hospital, Ministry of Health & WelfareTainan, Taiwan
| | - Jiunn-Jong Wu
- Department of Biotechnology and Laboratory Science in Medicine, School of Biomedical Science and Engineering, National Yang Ming University Taipei, Taiwan
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