The structure of the bacterial oxidoreductase enzyme DsbA in complex with a peptide reveals a basis for substrate specificity in the catalytic cycle of DsbA enzymes.

ABSTRACT: Oxidative protein folding in Gram-negative bacteria results in the formation of disulfide bonds between pairs of cysteine residues. This is a multistep process in which the dithiol-disulfide oxidoreductase enzyme, DsbA, plays a central role. The structure of DsbA comprises an all helical domain of unknown function and a thioredoxin domain, where active site cysteines shuttle between an oxidized, substrate-bound, reduced form and a DsbB-bound form, where DsbB is a membrane protein that reoxidizes DsbA. Most DsbA enzymes interact with a wide variety of reduced substrates and show little specificity. However, a number of DsbA enzymes have now been identified that have narrow substrate repertoires and appear to interact specifically with a smaller number of substrates. The transient nature of

SUBMITTER: Paxman JJ 

PROVIDER: S-EPMC2719422 | biostudies-literature | 2009 Jun

REPOSITORIES: biostudies-literature