2XXS
Solution structure of the N-terminal domain of the Shigella type III secretion protein MxiG
Summary for 2XXS
| Entry DOI | 10.2210/pdb2xxs/pdb |
| Descriptor | PROTEIN MXIG (1 entity in total) |
| Functional Keywords | pathogenesis, transport, protein binding, virulence, basal body structural component |
| Biological source | SHIGELLA FLEXNERI |
| Cellular location | Cell inner membrane; Single-pass type II membrane protein: P0A221 |
| Total number of polymer chains | 1 |
| Total formula weight | 12180.49 |
| Authors | McDowell, M.A.,Johnson, S.,Deane, J.E.,McDonnell, J.M.,Lea, S.M. (deposition date: 2010-11-11, release date: 2011-07-06, Last modification date: 2024-05-15) |
| Primary citation | Mcdowell, M.A.,Johnson, S.,Deane, J.E.,Cheung, M.,Roehrich, A.D.,Blocker, A.J.,Mcdonnell, J.M.,Lea, S.M. Structural and Functional Studies on the N-Terminal Domain of the Shigella Type III Secretion Protein Mxig. J.Biol.Chem., 286:30606-, 2011 Cited by PubMed Abstract: MxiG is a single-pass membrane protein that oligomerizes within the inner membrane ring of the Shigella flexneri type III secretion system (T3SS). The MxiG N-terminal domain (MxiG-N) is the predominant cytoplasmic structure; however, its role in T3SS assembly and secretion is largely uncharacterized. We have determined the solution structure of MxiG-N residues 6-112 (MxiG-N(6-112)), representing the first published structure of this T3SS domain. The structure shows strong structural homology to forkhead-associated (FHA) domains. Canonically, these cell-signaling modules bind phosphothreonine (Thr(P)) via highly conserved residues. However, the putative phosphate-binding pocket of MxiG-N(6-112) does not align with other FHA domain structures or interact with Thr(P). Furthermore, mutagenesis of potential phosphate-binding residues has no effect on S. flexneri T3SS assembly and function. Therefore, MxiG-N has a novel function for an FHA domain. Positioning of MxiG-N(6-112) within the EM density of the S. flexneri needle complex gives insight into the ambiguous stoichiometry of the T3SS, supporting models with 24 MxiG subunits in the inner membrane ring. PubMed: 21733840DOI: 10.1074/JBC.M111.243865 PDB entries with the same primary citation |
| Experimental method | SOLUTION NMR |
Structure validation
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