4mjw

Crystal Structure of Choline Oxidase in Complex with the Reaction Product Glycine Betaine

spinqualitylabelsall models 4mjw, resolution 1.95Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4mjw is a 2 chain structure with sequence from Arthrobacter globiformis. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.95Å Ligands: ACT, BET, FAD, GOL Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function CHOX_ARTGO Catalyzes the two-step oxidative conversion of choline to glycine-betaine with betaine aldehyde as an intermediate. Glycine-betaine accumulates to high levels in the cytoplasm of cells to prevent dehydration and plasmolysis in adverse hyperosmotic environments. Accepts either choline or the reaction intermediate betaine-aldehyde as substrate. Publication Abstract from PubMed Choline oxidase from Arthrobacter globiformis, which is involved in the biosynthesis of glycine betaine from choline, has been extensively characterized in its mechanistic and structural properties. Despite the knowledge gained on the enzyme, the details of substrate access to the active site are not fully understood. The `loop-and-lid' mechanism described for the glucose-methanol-choline enzyme superfamily has not been confirmed for choline oxidase. Instead, a hydrophobic cluster on the solvent-accessible surface of the enzyme has been proposed by molecular dynamics to control substrate access to the active site. Here, the crystal structure of the enzyme was solved in complex with glycine betaine at pH 6.0 at 1.95 A resolution, allowing a structural description of the ligand-enzyme interactions in the active site. This structure is the first of choline oxidase in complex with a physiologically relevant ligand. The protein structures with and without ligand are virtually identical, with the exception of a loop at the dimer interface, which assumes two distinct conformations. The different conformations of loop 250-255 define different accessibilities of the proposed active-site entrance delimited by the hydrophobic cluster on the other subunit of the dimer, suggesting a role in regulating substrate access to the active site. Structure of choline oxidase in complex with the reaction product glycine betaine.,Salvi F, Wang YF, Weber IT, Gadda G Acta Crystallogr D Biol Crystallogr. 2014 Feb;70(Pt 2):405-13. doi:, 10.1107/S1399004713029283. Epub 2014 Jan 29. PMID:24531474 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Choline Oxidase

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