Thioredoxin (TRX)-Glutaredoxin (GRX)-like family; composed of archaeal and bacterial proteins that show similarity to both TRX and GRX, including the C-terminal TRX-fold subdomain of Pyrococcus furiosus protein disulfide oxidoreductase (PfPDO). All members contain a redox-active CXXC motif and may function as PDOs. The archaeal proteins Mj0307 and Mt807 show structures more similar to GRX, but activities more similar to TRX. Some members of the family are similar to PfPDO in that they contain a second CXXC motif located in a second TRX-fold subdomain at the N-terminus; the superimposable N- and C-terminal TRX subdomains form a compact structure. PfPDO is postulated to be the archaeal counterpart of bacterial DsbA and eukaryotic protein disulfide isomerase (PDI). The C-terminal CXXC motif of PfPDO is required for its oxidase, reductase and isomerase activities. Also included in the family is the C-terminal TRX-fold subdomain of the N-terminal domain (NTD) of bacterial AhpF, which has a similar fold as PfPDO with two TRX-fold subdomains but without the second CXXC motif.
Jiyao W et al.(2023). "The conserved domain database in 2023.",