2itm | pdb_00002itm

Crystal structure of the E. coli xylulose kinase complexed with xylulose

spinqualitylabelsall models 2itm, resolution 2.10Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2itm is a 2 chain structure with sequence from "bacillus_coli"_migula_1895 "bacillus coli" migula 1895. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: NH4, SO4, XUL Gene: xylB ("Bacillus coli" Migula 1895) Activity: Xylulokinase, with EC number 2.7.1.17 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT 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 PubMed The primary metabolic route for D-xylose, the second most abundant sugar in nature, is via the pentose phosphate pathway after a two-step or three-step conversion to xylulose-5-phosphate. Xylulose kinase (XK; EC 2.7.1.17) phosphorylates D-xylulose, the last step in this conversion. The apo and D-xylulose-bound crystal structures of Escherichia coli XK have been determined and show a dimer composed of two domains separated by an open cleft. XK dimerization was observed directly by a cryo-EM reconstruction at 36 A resolution. Kinetic studies reveal that XK has a weak substrate-independent MgATP-hydrolyzing activity, and phosphorylates several sugars and polyols with low catalytic efficiency. Binding of pentulose and MgATP to form the reactive ternary complex is strongly synergistic. Although the steady-state kinetic mechanism of XK is formally random, a path is preferred in which D-xylulose binds before MgATP. Modelling of MgATP binding to XK and the accompanying conformational change suggests that sugar binding is accompanied by a dramatic hinge-bending movement that enhances interactions with MgATP, explaining the observed synergism. A catalytic mechanism is proposed and supported by relevant site-directed mutants. Structural and kinetic studies of induced fit in xylulose kinase from Escherichia coli.,Di Luccio E, Petschacher B, Voegtli J, Chou HT, Stahlberg H, Nidetzky B, Wilson DK J Mol Biol. 2007 Jan 19;365(3):783-98. Epub 2006 Oct 25. PMID:17123542 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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