3iss

Crystal structure of enolpyruvyl-UDP-GlcNAc synthase (MurA):UDP-N-acetylmuramic acid:phosphite from Escherichia coli

spinqualitylabelsall models 3iss, resolution 2.50Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3iss is a 12 chain structure with sequence from Escherichia coli K-12. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.5Å Ligands: EPU, PO3 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function MURA_ECOLI Cell wall formation. Adds enolpyruvyl to UDP-N-acetylglucosamine. Target for the antibiotic phosphomycin.[HAMAP-Rule:MF_00111] 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 MurA (enolpyruvyl UDP-GlcNAc synthase) catalyzes the first committed step in peptidoglycan biosynthesis. In this study, MurA-catalyzed breakdown of its tetrahedral intermediate (THI), with a k(cat)/K(M) of 520 M(-1) s(-1), was far slower than the normal reaction, and 3 x 10(5)-fold slower than the homologous enzyme, AroA, reacting with its THI. This provided kinetic evidence of slow binding and a conformationally constrained active site. The MurA cocrystal structure with UDP-N-acetylmuramic acid (UDP-MurNAc), a potent inhibitor, and phosphite revealed a new "staged" MurA conformation in which the Arg397 side chain tracked phosphite out of the catalytic site. The closed-to-staged transition involved breaking eight MurA.ligand ion pairs, and three intraprotein hydrogen bonds helping hold the active site loop closed. These were replaced with only two MurA.UDP-MurNAc ion pairs, two with phosphite, and seven new intraprotein ion pairs or hydrogen bonds. Cys115 appears to have an important role in forming the staged conformation. The staged conformation appears to be one step in a complex choreography of release of the product from MurA. Evidence of Kinetic Control of Ligand Binding and Staged Product Release in MurA (Enolpyruvyl UDP-GlcNAc Synthase)-Catalyzed Reactions .,Jackson SG, Zhang F, Chindemi P, Junop MS, Berti PJ Biochemistry. 2009 Nov 18. PMID:19899805 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Enoylpyruvate transferase 3D structures

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