PDBsum entry 2fjs

Oxidoreductase

PDB id: 2fjs

Contents

Protein chains

336 a.a. *

Ligands

ACT ×10

TRS

Metals

CU1 ×3

_CU ×3

Waters ×1106

* Residue conservation analysis

PDB id:

2fjs

Name:

Oxidoreductase

Title:

Crystal structure of anaerobically reduced wild type nitrite reductase from a. Faecalis

Structure:

Copper-containing nitrite reductase. Chain: a, b, c. Synonym: cu-nir. Engineered: yes

Source:

Alcaligenes faecalis. Organism_taxid: 511. Strain: s-6. Gene: nirk, nir. Expressed in: escherichia coli bl21. Expression_system_taxid: 511693.

Biol. unit:

Trimer (from PQS)

Resolution:

1.85Å R-factor: 0.152 R-free: 0.180

Authors:

E.I.Tocheva,M.E.P.Murphy

Key ref:

H.J.Wijma et al. (2007). Effect of the methionine ligand on the reorganization energy of the type-1 copper site of nitrite reductase. J Am Chem Soc, 129, 519-525. PubMed id: 17227014 DOI: 10.1021/ja064763j

Date:

03-Jan-06 Release date: 21-Nov-06

Protein chains

P38501  (NIR_ALCFA) -  Copper-containing nitrite reductase from Alcaligenes faecalis

Seq: 376 a.a.

Struc: 336 a.a.

Enzyme reactions

• Enzyme class: E.C.1.7.2.1 - nitrite reductase (NO-forming).
• Reaction: nitric oxide + Fe(III)-[cytochrome c] + H2O = Fe(II)-[cytochrome c] + nitrite + 2 H⁺
• Cofactor: Cu cation or Fe cation; FAD

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

reference

DOI no: 10.1021/ja064763j

J Am Chem Soc 129:519-525 (2007)

PubMed id: 17227014

Effect of the methionine ligand on the reorganization energy of the type-1 copper site of nitrite reductase.

H.J.Wijma, I.MacPherson, O.Farver, E.I.Tocheva, I.Pecht, M.P.Verbeet, M.E.Murphy, G.W.Canters.

ABSTRACT

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.