bacterioferritin-associated ferredoxin (BFD)-like [2Fe-2S]-binding domain of the alpha-subunit of archaeal proline dehydrogenase PDH1
This domain family describes the alpha-subunit of archaeal dye-linked L-proline dehydrogenase PDH1. Dye-linked PDH catalyzes the oxidation of L-proline to 1-pyrroline-5-carboxylate in the presence of artificial electron acceptors. It includes the alpha subunit of Pyrococcus horikoshii PHD1 which has been shown to exist as an (alphabeta)4 heterooctamer and to contain three cofactors: FAD, FMN, and ATP; the alpha subunit contains ATP but exhibits no PDH activity, the beta subunit is the catalytic component contains FAD and exhibits PDH activity, and FMN is located between the alpha and beta subunits. The BFD-like [2Fe-2S]-binding domain is found in a variety of other proteins including bacterioferritin-associated ferredoxin (BFD), the large subunit of NADH-dependent nitrite reductase, and Cu+ chaperone CopZ. It comprises a helix-turn-helix fold, and binds an [2Fe-2S] cluster via 4 highly-conserved Cys residues, found in loops between the alpha-helices. For the class of proteins having a BFD-like [2Fe-2S]-binding domain, the Cys residues are organized in a unique C-X2-C-X31-35-C-X2-9-C-arrangement. [2Fe-2S] clusters are sulfide-linked diiron centers, a primary role for which is electron transport.
Comment:based on BFD-like [2Fe-2S]-binding domains bound to an [2Fe-2S] cluster, and on Pirococcus horikoshii PDH1 alpha subunit bound with Fe3+ in the [2Fe-2S]-binding site
Jiyao W et al.(2023). "The conserved domain database in 2023.",