ISSN: 0973-7510

E-ISSN: 2581-690X

Research Article | Open Access
Swagata Sain1, Sukriti Sacher2, Bhawna Solanki1 and Navin Kumar1
1School of Biotechnology, Gautam Buddha University, Greater Noida, Uttar Pradesh, India.
2Department of Computational Biology, Indraprastha Institute of Information Technology-Delhi, New Delhi, India.
Article Number: 10483| © The Author(s). 2025
J Pure Appl Microbiol. 2025;19(3):2042-2053. https://doi.org/10.22207/JPAM.19.3.29
Received: 18 April 2025 | Accepted: 17 July 2025 | Published online: 23 August 2025
Issue online: September 2025
Abstract

Helicobacter pylori’s type IV secretion system (T4SS) is a key virulence determinant, mediating the delivery of effector proteins such as cytotoxin-associated gene A (CagA) into host epithelial cells. Despite its significance, the molecular architecture and assembly dynamics of the inner membrane core complex within the Cag-T4SS remain inadequately resolved. This study aimed to identify and characterize the direct interaction between CagF, a chaperone protein, and CagV, an inner membrane-associated component of the Cag-T4SS. Immunoprecipitation and pull-down assays confirm the physical interaction between CagF and CagV. Computational docking and molecular dynamics simulations further elucidated the binding interface, revealing a stable interaction mediated by electrostatic complementarity, hydrogen bonding, and salt bridges. Co-expression and pull-down experiments using recombinant proteins validated these findings. Notably, deletion analysis identified the critical role of the N-terminal region (residues 50-100) of CagF in CagV binding, further supporting the computational predictions. Given the essential role of CagV in CagA translocation, we hypothesize that CagF-CagV interaction may facilitate the localization of the CagF-CagA complex near the secretion channel, promoting efficient effector translocation. These findings enhance our understanding of the Cag-secretion system’s structural organization and biogenesis.

Keywords

H. pylori, Cag-type IV Secretion System, CagA, CagF, CagV

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© The Author(s) 2025. Open Access. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License which permits unrestricted use, sharing, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.