8YNX

Crystal structure of Cag3-CagT complex from Helicobacter pylori

Summary for 8YNX

• Entry DOI: 10.2210/pdb8ynx/pdb
• Descriptor: Cag pathogenicity island protein 3, Cag pathogenicity island protein T (3 entities in total)
• Functional Keywords: type iv secretion system, helicobacter pylori, structural protein
• Biological source: Helicobacter pylori (strain G27); More
• Total number of polymer chains: 2
• Total formula weight: 38446.70

Authors

Mok, C.Y.,Au, S.W.N. (deposition date: 2024-03-12, release date: 2025-03-19, Last modification date: 2025-04-16)

Primary citation

Mok, C.Y.,Chu, H.Y.,Lam, W.W.L.,Au, S.W.N.
Structural insights into the assembly pathway of the Helicobacter pylori CagT4SS outer membrane core complex.
Structure, 32:1725-1736.e4, 2024

PubMed Abstract: Cag type IV secretion system (CagT4SS) translocates oncoprotein cytotoxin-associated gene A (CagA) into host cells and plays a key role in the pathogenesis of Helicobacter pylori. The structure of the outer membrane core complex (OMCC) in CagT4SS consists of CagX, CagY, CagM, CagT, and Cag3 in a stoichiometric ratio of 1:1:2:2:5 with 14-fold symmetry. However, the assembly pathway of OMCC remains elusive. Here, we report the crystal structures of CagT and Cag3-CagT complex, and the structural dynamics of Cag3 and CagT using hydrogen deuterium exchange-mass spectrometry (HDX-MS). The interwoven interaction of Cag3 and CagT involves conformational changes of CagT and β strand swapping. In conjunction with biochemical and biophysical assays, we further demonstrate the different oligomerization states of Cag3 and Cag3-CagT complex. Additionally, the association with CagM requires the pre-formation of Cag3-CagT complex. These results demonstrate the generation of different intermediate sub-assemblies and their structural flexibility, potentially representing different building blocks for OMCC assembly.

PubMed: 39032488
DOI: 10.1016/j.str.2024.06.019

Experimental method

X-RAY DIFFRACTION (3.25 Å)