Uncoupling binding of substrate CO from turnover by vanadium nitrogenase.
Proc Natl Acad Sci U S A
; 112(45): 13845-9, 2015 Nov 10.
Article
em En
| MEDLINE
| ID: mdl-26515097
ABSTRACT
Biocatalysis by nitrogenase, particularly the reduction of N2 and CO by this enzyme, has tremendous significance in environment- and energy-related areas. Elucidation of the detailed mechanism of nitrogenase has been hampered by the inability to trap substrates or intermediates in a well-defined state. Here, we report the capture of substrate CO on the resting-state vanadium-nitrogenase in a catalytically competent conformation. The close resemblance of this active CO-bound conformation to the recently described structure of CO-inhibited molybdenum-nitrogenase points to the mechanistic relevance of sulfur displacement to the activation of iron sites in the cofactor for CO binding. Moreover, the ability of vanadium-nitrogenase to bind substrate in the resting-state uncouples substrate binding from subsequent turnover, providing a platform for generation of defined intermediate(s) of both CO and N2 reduction.
Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Monóxido de Carbono
/
Nitrogenase
Idioma:
En
Ano de publicação:
2015
Tipo de documento:
Article