The 3D-structure, kinetics and dynamics of the E. coli nitroreductase NfsA with NADP+ provide glimpses of its catalytic mechanism.
FEBS Lett
; 596(18): 2425-2440, 2022 09.
Article
en En
| MEDLINE
| ID: mdl-35648111
ABSTRACT
Nitroreductases activate nitroaromatic antibiotics and cancer prodrugs to cytotoxic hydroxylamines and reduce quinones to quinols. Using steady-state and stopped-flow kinetics, we show that the Escherichia coli nitroreductase NfsA is 20-50 fold more active with NADPH than with NADH and that product release may be rate-limiting. The crystal structure of NfsA with NADP+ shows that a mobile loop forms a phosphate-binding pocket. The nicotinamide ring and nicotinamide ribose are mobile, as confirmed in molecular dynamics (MD) simulations. We present a model of NADPH bound to NfsA. Only one NADP+ is seen bound to the NfsA dimers, and MD simulations show that binding of a second NADP(H) cofactor is unfavourable, suggesting that NfsA and other members of this protein superfamily may have a half-of-sites mechanism.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Profármacos
/
Proteínas de Escherichia coli
Idioma:
En
Revista:
FEBS Lett
Año:
2022
Tipo del documento:
Article
País de afiliación:
Reino Unido