4loc

Structure of the carboxyl transferase domain from Rhizobium etli pyruvate carboxylase with oxamate and biotin

spinqualitylabelsall models 4loc, resolution 2.26Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4loc is a 4 chain structure. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: BTN, CL, GOL, MG, OXM, ZN NonStd Res: KCX Related: 4jx6, 4jx5, 4jx4, 3tw6, 2qf7, 4m6v, 4mfd, 4mfe, 4mim Activity: Pyruvate carboxylase, with EC number 6.4.1.1 Resources: FirstGlance, OCA, RCSB, PDBsum Publication Abstract from PubMed Pyruvate carboxylase (PC) is a biotin-dependent enzyme that catalyzes the MgATP-dependent carboxylation of pyruvate to oxaloacetate, an important anaplerotic reaction in central metabolism. During catalysis, carboxybiotin is translocated to the carboxyltransferase domain where the carboxyl group is transferred to the acceptor substrate, pyruvate. Many studies on the carboxyltransferase domain of PC have demonstrated an enhanced oxaloacetate decarboxylation activity in the presence of oxamate and it has been shown that oxamate accepts a carboxyl group from carboxybiotin during oxaloacetate decarboxylation. The X-ray crystal structure of the carboxyltransferase domain from Rhizobium etli PC reveals that oxamate is positioned in the active site in an identical manner to the substrate, pyruvate, and kinetic data are consistent with the oxamate-stimulated decarboxylation of oxaloacetate proceeding through a simple ping-pong bi bi mechanism in the absence of the biotin carboxylase domain. Additionally, analysis of truncated PC enzymes indicates that the BCCP domain devoid of biotin does not contribute directly to the enzymatic reaction and conclusively demonstrates a biotin-independent oxaloacetate decarboxylation activity in PC. These findings advance the description of catalysis in PC and can be extended to the study of related biotin-dependent enzymes. The role of biotin and oxamate in the carboxyl transferase reaction of pyruvate carboxylase.,Lietzan AD, Lin Y, St Maurice M Arch Biochem Biophys. 2014 Aug 23. pii: S0003-9861(14)00308-7. doi:, 10.1016/j.abb.2014.08.008. PMID:25157442 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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