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Cited by 6Advanced Electron Microscopy Techniques and ApplicationsHelicobacter pylori-related gastroenterology studiesBacterial Genetics and Biotechnology

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Assembly and glycosylation of Helicobacter pylori sheathed flagella

Open access
Kumar, Rajeev, Tachiyama, Shoichi, Yu, Huaxin, Heydari, Samira, Guo, Jiaqi, Botting, Jack M, Guo, Wangbiao, Hoover, Timothy R, Liu, Jun·2026·PNAS Nexus
DOI 10.1093/pnasnexus/pgag011PMC PMC12880188

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Abstract

The bacterial flagellum is a complex nanomachine essential for motility, colonization, and invasion in diverse species. Helicobacter pylori has evolved elaborate sheathed flagella that enable migration through the highly viscous gastric mucus layer to reach its colonization niche on the gastric epithelium, yet the molecular basis for these unique adaptations has remained elusive. Here, we use in situ single-particle cryo-electron microscopy to determine near-atomic structures of the flagellar filament within the membranous sheath of H. pylori. The major flagellin FlaA constitutes the bulk of the filament, whereas the minor flagellin FlaB contributes critically to the hook-proximal region. Both FlaA and FlaB form a conserved core surrounded by variable surface-exposed domains. Our structures further reveal that pseudaminic acid glycans decorate these domains, where they mediate inter- and intra-subunit contacts that stabilize the filament and confer a negatively charged surface. Together, these findings support a model in which the filament rotates independently of the membranous sheath to drive H. pylori motility and provide a molecular framework for understanding how the sheathed flagellum enables colonization and persistence within the gastric niche.

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Metadata

Authors
Kumar, R., Tachiyama, S., Yu, H., Heydari, S., Guo, J., Botting, J. M., Guo, W., Hoover, T. R., & Liu, J.
Affiliations
  • Yale University (US)
  • University of Georgia (US)
Corresponding author
  • Hoover, Timothy R
  • Liu, Jun
ORCID
Venue
PNAS Nexus
Publisher
Oxford University Press (OUP)
Published
2026-01-20
Volume
5
Issue
2
Pages
pgag011-pgag011
ISSN
2752-6542 (ISSN-L)
DOI
10.1093/pnasnexus/pgag011
PMC
PMC12880188
OpenAlex
W7124885610
Cited by
6
References
2
Citations by year
2026: 6
FWCI
11.85
Type
journal article
Language
en
Open access
Licence
Locations
  • PNAS Nexus (publishedVersion, cc-by)
  • bioRxiv (Cold Spring Harbor Laboratory) (acceptedVersion)
  • Europe PMC (PubMed Central) (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • PubMed Central (submittedVersion)
Funders
  • National Institute of Allergy and Infectious Diseases (R01AI189907, R01AI087946, R01AI132818)
  • National Institutes of Health
Topics
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Structural Biology › Advanced Electron Microscopy Techniques and Applications
  • Health Sciences › Medicine › Gastroenterology › Helicobacter pylori-related gastroenterology studies
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Genetics › Bacterial Genetics and Biotechnology
Keywords
Helicobacter pylori, glycosylation, bacterial motility, single-particle cryo-electron microscopy

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