3la6 | pdb_00003la6
From Proteopedia
Octameric kinase domain of the E. coli tyrosine kinase Wzc with bound ADP
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Structural highlights
Function[WZC_ECOLI] Required for the extracellular polysaccharide colanic acid synthesis. The autophosphorylated form is inactive. Probably involved in the export of colanic acid from the cell to medium. Phosphorylates udg. Evolutionary Conservation![]() Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedCapsular polysaccharides are well-established virulence factors of pathogenic bacteria. Their biosynthesis and export are regulated within the transmembrane polysaccharide assembly machinery by the autophosphorylation of atypical tyrosine-kinases, named BY-kinases. However, the accurate functioning of these tyrosine-kinases remains unknown. Here, we report the crystal structure of the non-phosphorylated cytoplasmic domain of the tyrosine-kinase Wzc from Escherichia coli in complex with ADP showing that it forms a ring-shaped octamer. Mutational analysis demonstrates that a conserved EX(2)RX(2)R motif involved in subunit interactions is essential for polysaccharide export. We also elucidate the role of a putative internal regulatory tyrosine and we show that BY-kinases from proteobacteria autophosphorylate on their C-terminal tyrosine cluster via a single step intermolecular mechanism. This structure-function analysis also allows us to demonstrate that two different parts of a conserved basic region called the RK-cluster are essential for polysaccharide export and for kinase activity, respectively. Based on these data, we revisit the dichotomy made between BY-kinases from proteobacteria and firmicutes and we propose a unique process of oligomerization and phosphorylation. We also reassess the function of BY-kinases in the capsular polysaccharide assembly machinery. Identification of structural and molecular determinants of the tyrosine-kinase Wzc and implications in capsular polysaccharide export.,Bechet E, Gruszczyk J, Terreux R, Gueguen-Chaignon V, Vigouroux A, Obadia B, Cozzone AJ, Nessler S, Grangeasse C Mol Microbiol. 2010 Jul 13. PMID:20633230[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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This page was last modified 20:23, 5 August 2016.