The 3D-structure, kinetics and dynamics of the E. coli nitroreductase NfsA with NADP + provide glimpses of its catalytic mechanism.

Autor: White SA; School of Biosciences, University of Birmingham, UK., Christofferson AJ; School of Science, RMIT University, Melbourne, Australia., Grainger AI; School of Biosciences, University of Birmingham, UK., Day MA; School of Biosciences, University of Birmingham, UK.; Institute for Cancer and Genomic Sciences, University of Birmingham, UK., Jarrom D; School of Biosciences, University of Birmingham, UK., Graziano AE; School of Biosciences, University of Birmingham, UK., Searle PF; Institute for Cancer and Genomic Sciences, University of Birmingham, UK., Hyde EI; School of Biosciences, University of Birmingham, UK.
Jazyk: angličtina
Zdroj: FEBS letters [FEBS Lett] 2022 Sep; Vol. 596 (18), pp. 2425-2440. Date of Electronic Publication: 2022 Jul 13.
DOI: 10.1002/1873-3468.14413
Abstrakt: 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.
(© 2022 Federation of European Biochemical Societies.)
Databáze: MEDLINE
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