2XXS

Solution structure of the N-terminal domain of the Shigella type III secretion protein MxiG

2XXS の概要

• エントリーDOI: 10.2210/pdb2xxs/pdb
• 分子名称: PROTEIN MXIG (1 entity in total)
• 機能のキーワード: pathogenesis, transport, protein binding, virulence, basal body structural component
• 由来する生物種: SHIGELLA FLEXNERI
• 細胞内の位置: Cell inner membrane; Single-pass type II membrane protein: P0A221
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 12180.49

構造登録者

McDowell, M.A.,Johnson, S.,Deane, J.E.,McDonnell, J.M.,Lea, S.M. (登録日: 2010-11-11, 公開日: 2011-07-06, 最終更新日: 2024-05-15)

主引用文献

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

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: 21733840
DOI: 10.1074/JBC.M111.243865

実験手法

SOLUTION NMR