1et8

CRYSTAL STRUCTURE OF NITRITE REDUCTASE HIS255ASN MUTANT FROM ALCALIGENES FAECALIS

spinqualitylabelsall models 1et8, resolution 1.80Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1et8 is a 1 chain structure with sequence from Alcfa. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: CU, ZN Related: 1et5, 1et7, 2afn, 1as7 Activity: Nitrite reductase (NO-forming), with EC number 1.7.2.1 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 Two active site residues, Asp-98 and His-255, of copper-containing nitrite reductase (NIR) from Alcaligenes faecalis have been mutated to probe the catalytic mechanism. Three mutations at these two sites (D98N, H255D, and H255N) result in large reductions in activity relative to native NIR, suggesting that both residues are involved intimately in the reaction mechanism. Crystal structures of these mutants have been determined using data collected to better than 1. 9-A resolution. In the native structure, His-255 Nepsilon2 forms a hydrogen bond through a bridging water molecule to the side chain of Asp-98, which also forms a hydrogen bond to a water or nitrite oxygen ligated to the active site copper. In the D98N mutant, reorientation of the Asn-98 side chain results in the loss of the hydrogen bond to the copper ligand water, consistent with a negatively charged Asp-98 directing the binding and protonation of nitrite in the native enzyme. An additional solvent molecule is situated between residues 255 and the bridging water in the H255N and H255D mutants and likely inhibits nitrite binding. The interaction of His-255 with the bridging water appears to be necessary for catalysis and may donate a proton to reaction intermediates in addition to Asp-98. Catalytic roles for two water bridged residues (Asp-98 and His-255) in the active site of copper-containing nitrite reductase.,Boulanger MJ, Kukimoto M, Nishiyama M, Horinouchi S, Murphy ME J Biol Chem. 2000 Aug 4;275(31):23957-64. PMID:10811642 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Nitrite reductase

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