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PDBsum entry 2fjs
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Oxidoreductase
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PDB id
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2fjs
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References listed in PDB file
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Key reference
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Title
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Effect of the methionine ligand on the reorganization energy of the type-1 copper site of nitrite reductase.
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Authors
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H.J.Wijma,
I.Macpherson,
O.Farver,
E.I.Tocheva,
I.Pecht,
M.P.Verbeet,
M.E.Murphy,
G.W.Canters.
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Ref.
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J Am Chem Soc, 2007,
129,
519-525.
[DOI no: ]
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PubMed id
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Abstract
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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.
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