View source for 4tt9


==Structure of the C-terminal SpoA domain of Shigella flexneri Spa33==
<StructureSection load='4tt9' size='340' side='right'caption='[[4tt9]], [[Resolution|resolution]] 2.30&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4tt9]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Shigella_flexneri Shigella flexneri]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4TT9 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4TT9 FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=4tt9 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4tt9 OCA], [https://pdbe.org/4tt9 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4tt9 RCSB], [https://www.ebi.ac.uk/pdbsum/4tt9 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4tt9 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/SPAO_SHIFL SPAO_SHIFL] Required for surface presentation of invasion plasmid antigens. Could play a role in preserving the translocation competence of the Ipa antigens. Required for invasion and for secretion of the three Ipa proteins.
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== Publication Abstract from PubMed ==
Flagellar Type III secretion systems (T3SS) contain an essential Cytoplasmic-ring (C-ring) largely composed of two proteins FliM and FliN, whilst an analogous substructure for the closely related non-flagellar (NF) T3SS has not been observed in situ. We show that the spa33 gene encoding the putative NF-T3SS C-ring component in Shigella flexneri is alternatively translated to produce both full-length (Spa33-FL) and a short variant (Spa33-C), with both required for secretion. They associate in a 1:2 complex (Spa33-FL/C2 ) that further oligomerises into elongated arrays in vitro. The structure of Spa33-C2 and identification of an unexpected intramolecular pseudodimer in Spa33-FL, reveals a molecular model for their higher order assembly within NF-T3SS. Spa33-FL and Spa33-C are identified as functional counterparts of a FliM-FliN fusion and free FliN respectively. Furthermore, we show that Thermotoga maritima FliM and FliN form a 1:3 complex structurally equivalent to Spa33-FL/C2 , allowing us to propose a unified model for C-ring assembly by NF-T3SS and flagellar-T3SS.

Characterisation of Shigella Spa33 and Thermotoga FliM/N reveals a new model for C-ring assembly in T3SS.,McDowell MA, Marcoux J, McVicker G, Johnson S, Fong YH, Stevens R, Bowman LA, Degiacomi MT, Yan J, Wise A, Friede M, Benesch JL, Deane JE, Tang CM, Robinson CV, Lea SM Mol Microbiol. 2015 Nov 5. doi: 10.1111/mmi.13267. PMID:26538516<ref>PMID:26538516</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 4tt9" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Large Structures]]
[[Category: Shigella flexneri]]
[[Category: Johnson S]]
[[Category: Lea SM]]
[[Category: McDowell MA]]