Download MendeleyThe 3D-structure, kinetics and dynamics of the E. coli nitroreductase NfsA with NADP + provide glimpses of its catalytic mechanism.
White, S.A., Christofferson, A.J., Grainger, A.I., Day, M.A., Jarrom, D., Graziano, A.E., Searle, P.F., Hyde, E.I.(2022) FEBS Lett 596: 2425-2440
- PubMed: 35648111
- DOI: https://doi.org/10.1002/1873-3468.14413
- Primary Citation of Related Structures:
7Q0O, 7Z0W - PubMed 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.
Organizational Affiliation:
School of Biosciences, University of Birmingham, UK.
