Cryo-EM reveals species-specific components within the Helicobacter pylori Cag type IV secretion system core complex
| Autor: | Jeong Min Chung, Michael J Sheedlo, Melanie D. Ohi, Timothy L. Cover, Neha Sawhney, D. Borden Lacy, Clarissa L Durie |
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| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
0301 basic medicine
Cryo-electron microscopy QH301-705.5 Science 030106 microbiology cryo-electron microscopy bacterial protein secretion General Biochemistry Genetics and Molecular Biology 03 medical and health sciences Molar ratio CagA Secretion Helicobacter Biology (General) molecular machine General Immunology and Microbiology biology Helicobacter pylori Chemistry General Neuroscience gastric cancer General Medicine Periplasmic space biology.organism_classification Molecular biology 030104 developmental biology type iv secretion Medicine Bacterial outer membrane |
| Zdroj: | eLife, Vol 9 (2020) |
| Popis: | The pathogenesis of Helicobacter pylori-associated gastric cancer is dependent on delivery of CagA into host cells through a type IV secretion system (T4SS). The H. pylori 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 H. pylori T4SS core complex is dependent on incorporation of interwoven species-specific components. |
| Databáze: | OpenAIRE |
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