2fjs
From Proteopedia
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Crystal Structure of Anaerobically Reduced Wild Type Nitrite Reductase from A. faecalis
Overview
Copper-containing nitrite reductase harbors a type-1 and a type-2 Cu site. The former acts as the electron acceptor site of the enzyme, and the latter is the site of catalytic action. The effect of the methionine ligand on the reorganization energy of the type-1 site was explored by studying the electron-transfer kinetics between NiR (wild type (wt) and the variants Met150Gly and Met150Thr) with Fe(II)EDTA and Fe(II)HEDTA. The mutations increased the reorganization energy by 0.3 eV (30 kJ mol-1). A similar increase was found from pulse radiolysis experiments on the wt NIR and three variants (Met150Gly, Met150His, and Met150Thr). Binding of the nearby Met62 to the type-1 Cu site in Met150Gly (under influence of an allosteric effector) lowered the reorganization energy back to approximately the wt value. According to XRD data the structure of the reduced type-1 site in Met150Gly NiR in the presence of an allosteric effector is similar to that in the reduced wt NiR (solved to 1.85 A), compatible with the similarity in reorganization energy.
About this Structure
2FJS is a Single protein structure of sequence from Alcaligenes faecalis with , , and as ligands. Active as Nitrite reductase (NO-forming), with EC number 1.7.2.1 Full crystallographic information is available from OCA.
Reference
Effect of the methionine ligand on the reorganization energy of the type-1 copper site of nitrite reductase., Wijma HJ, MacPherson I, Farver O, Tocheva EI, Pecht I, Verbeet MP, Murphy ME, Canters GW, J Am Chem Soc. 2007 Jan 24;129(3):519-25. PMID:17227014
Page seeded by OCA on Thu Feb 21 17:22:13 2008
