High-resolution crystal structures reveal a mixture of conformers of the Gly61-Asp62 peptide bond in an oxidized flavodoxin from Bacillus cereus.

ABSTRACT: Flavodoxins (Flds) are small proteins that shuttle electrons in a range of reactions in microorganisms. Flds contain a redox-active cofactor, a flavin mononucleotide (FMN), and it is well established that when Flds are reduced by one electron, a peptide bond close to the FMN isoalloxazine ring flips to form a new hydrogen bond with the FMN N5H, stabilizing the one-electron reduced state. Here, we present high-resolution crystal structures of Flavodoxin 1 from Bacillus cereus in both the oxidized (ox) and one-electron reduced (semiquinone, sq) state. We observe a mixture of conformers in the oxidized state; a 50:50 distribution between the established oxidized conformation where the peptide bond is pointing away from the flavin, and a conformation where the peptide bond is pointing toward t

SUBMITTER: Gudim I 

PROVIDER: S-EPMC6153408 | biostudies-literature | 2018 Aug

REPOSITORIES: biostudies-literature