6X6K

Cryo-EM Structure of the Helicobacter pylori dCag3 OMC

This is a non-PDB format compatible entry.

Summary for 6X6K

• Entry DOI: 10.2210/pdb6x6k/pdb
• EMDB information: 22076
• Descriptor: Cag pathogenicity island protein, Type IV secretion system apparatus protein CagX, Cag pathogenicity island protein (Cag7) (3 entities in total)
• Functional Keywords: helicobacter, t4ss, secretion, protein transport
• Biological source: Helicobacter pylori; More
• Total number of polymer chains: 42
• Total formula weight: 4377826.03

Authors

Sheedlo, M.J.,Chung, J.M.,Sawhney, N.,Durie, C.L.,Cover, T.L.,Ohi, M.D.,Lacy, D.B. (deposition date: 2020-05-28, release date: 2020-10-07, Last modification date: 2024-03-06)

Primary citation

Sheedlo, M.J.,Chung, J.M.,Sawhney, N.,Durie, C.L.,Cover, T.L.,Ohi, M.D.,Lacy, D.B.
Cryo-EM reveals species-specific components within the Helicobacter pylori Cag type IV secretion system core complex.
Elife, 9:-, 2020

PubMed Abstract: The pathogenesis of -associated gastric cancer is dependent on delivery of CagA into host cells through a type IV secretion system (T4SS). The Cag T4SS includes a large membrane-spanning core complex containing five proteins, organized into an outer membrane cap (OMC), a periplasmic ring (PR) and a stalk. Here, we report cryo-EM reconstructions of a core complex lacking Cag3 and an improved map of the wild-type complex. We define the structures of two unique species-specific components (Cag3 and CagM) and show that Cag3 is structurally similar to CagT. Unexpectedly, components of the OMC are organized in a 1:1:2:2:5 molar ratio (CagY:CagX:CagT:CagM:Cag3). CagX and CagY are components of both the OMC and the PR and bridge the symmetry mismatch between these regions. These results reveal that assembly of the T4SS core complex is dependent on incorporation of interwoven species-specific components.

PubMed: 32876048
DOI: 10.7554/eLife.59495

Experimental method

ELECTRON MICROSCOPY (3.1 Å)