DCC proteins: a novel family of thiol-disulfide oxidoreductases

Using top-of-the-range fold-recognition methods, we have assigned a thioredoxin-like structure to a family of previously uncharacterized hypothetical proteins of bacterial origin. The DCC family, named after the conserved N-terminal DxxCxxC motif, encompasses proteins of unknown function from DUF393 (in Pfam database) and COG3011. The presence of two invariant potentially catalytic cysteine residues indicates that DCC proteins function as thiol-disulfide oxidoreductases.