Database of articles cited by EMDB/PDB/SASBDB data

Keywords
Structure methods	All X-ray diffraction NMR electron microscopy small angle scattering neutron diffraction fiber diffraction powder diffraction infrared spectroscopy EPR fluorescence transfer theoretical model Hybrid
Author
Journal
IF	>30 >20 >10 >5 all

Title	Three-dimensional electron microscopy reconstruction and cysteine-mediated crosslinking provide a model of the type III secretion system needle tip complex.
Journal, issue, pages	Mol Microbiol, Vol. 95, Issue 1, Page 31-50, Year 2015
Publish date	Nov 27, 2014
Authors	Martin Cheung / Da-Kang Shen / Fumiaki Makino / Takayuki Kato / A Dorothea Roehrich / Isabel Martinez-Argudo / Matthew L Walker / Isabel Murillo / Xia Liu / Maria Pain / James Brown / Gordon Frazer / Judith Mantell / Petros Mina / Thomas Todd / Richard B Sessions / Keiichi Namba / Ariel J Blocker /
PubMed Abstract	Type III secretion systems are found in many Gram-negative bacteria. They are activated by contact with eukaryotic cells and inject virulence proteins inside them. Host cell detection requires a ...Type III secretion systems are found in many Gram-negative bacteria. They are activated by contact with eukaryotic cells and inject virulence proteins inside them. Host cell detection requires a protein complex located at the tip of the device's external injection needle. The Shigella tip complex (TC) is composed of IpaD, a hydrophilic protein, and IpaB, a hydrophobic protein, which later forms part of the injection pore in the host membrane. Here we used labelling and crosslinking methods to show that TCs from a ΔipaB strain contain five IpaD subunits while the TCs from wild-type can also contain one IpaB and four IpaD subunits. Electron microscopy followed by single particle and helical image analysis was used to reconstruct three-dimensional images of TCs at ∼ 20 Å resolution. Docking of an IpaD crystal structure, constrained by the crosslinks observed, reveals that TC organisation is different from that of all previously proposed models. Our findings suggest new mechanisms for TC assembly and function. The TC is the only site within these secretion systems targeted by disease-protecting antibodies. By suggesting how these act, our work will allow improvement of prophylactic and therapeutic strategies.
External links	Mol Microbiol / PubMed:25353930 / PubMed Central
Methods	EM (single particle)
Resolution	19.0 - 24.0 Å
Structure data	2801 4d3e EMDB-2801: Negative stain electron microscopy reconstruction of the wild type tip complex from the type III secretion system of Shigella flexneri PDB-4d3e: Tetramer of IpaD, modified from 2J0O, fitted into negative stain electron microscopy reconstruction of the wild type tip complex from the type III secretion system of Shigella flexneri Method: EM (single particle) / Resolution: 24.0 Å EMDB-2802: Negative stain electron microscopy reconstruction of the tip complex from the type III secretion system of Shigella flexneri lacking IpaB Method: EM (single particle) / Resolution: 23.0 Å EMDB-2803: Negative stain electron microscopy reconstruction of the tip complex and needle from the type III secretion system of Shigella flexneri with MxiH mutation P44A Method: EM (single particle) / Resolution: 23.0 Å EMDB-2804: Negative stain electron microscopy reconstruction of the tip complex from the type III secretion system of Shigella flexneri with MxiH mutation Q51A Method: EM (single particle) / Resolution: 21.0 Å EMDB-2805: Refined negative stain electron microscopy reconstruction of the tip complex from the type III secretion system of Shigella flexneri with MxiH mutation Q51A Method: EM (single particle) / Resolution: 19.0 Å EMDB-2806: Negative stain electron microscopy reconstruction of the tip complex from the type III secretion system of Shigella flexneri with MxiH mutations P44A+Q51A Method: EM (single particle) / Resolution: 24.0 Å
Source	Shigella flexneri (bacteria) shigella flexneri 5a str. m90t (bacteria)
Keywords	CELL INVASION / TIP COMPLEX / TYPE III SECRETION SYSTEM / SHIGELLA FLEXNERI / WILD TYPE / IPAD