The nitrogenase FeMo-cofactor and P-cluster pair: 2.2 A resolution structures.
Science
; 260(5109): 792-4, 1993 May 07.
Article
em En
| MEDLINE
| ID: mdl-8484118
ABSTRACT
Structures recently proposed for the FeMo-cofactor and P-cluster pair of the nitrogenase molybdenum-iron (MoFe)-protein from Azotobacter vinelandii have been crystallographically verified at 2.2 angstrom resolution. Significantly, no hexacoordinate sulfur atoms are observed in either type of metal center. Consequently, the six bridged iron atoms in the FeMo-cofactor are trigonally coordinated by nonprotein ligands, although there may be some iron-iron bonding interactions that could provide a fourth coordination interaction for these sites. Two of the cluster sulfurs in the P-cluster pair are very close together (approximately 2.1 angstroms), indicating that they form a disulfide bond. These findings indicate that a cavity exists in the interior of the FeMo-cofactor that could be involved in substrate binding and suggest that redox reactions at the P-cluster pair may be linked to transitions of two cluster-bound sulfurs between disulfide and sulfide oxidation states.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Enxofre
/
Azotobacter vinelandii
/
Ferro
/
Molibdoferredoxina
/
Nitrogenase
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Science
Ano de publicação:
1993
Tipo de documento:
Article