Mutants of Cytochrome P450 Reductase Lacking Either Gly-141 or Gly-143 Destabilize Its FMN Semiquinone.

ABSTRACT: NADPH-cytochrome P450 oxidoreductase transfers electrons from NADPH to cytochromes P450 via its FAD and FMN. To understand the biochemical and structural basis of electron transfer from FMN-hydroquinone to its partners, three deletion mutants in a conserved loop near the FMN were characterized. Comparison of oxidized and reduced wild type and mutant structures reveals that the basis for the air stability of the neutral blue semiquinone is protonation of the flavin N5 and strong H-bond formation with the Gly-141 carbonyl. The ΔGly-143 protein had moderately decreased activity with cytochrome P450 and cytochrome c It formed a flexible loop, which transiently interacts with the flavin N5, resulting in the generation of both an unstable neutral blue semiquinone and hydroquinone. The ΔGly-141 a

SUBMITTER: Rwere F 

PROVIDER: S-EPMC4938185 | biostudies-literature | 2016 Jul

REPOSITORIES: biostudies-literature