InterPro domain: IPR036644

Ferredoxin thioredoxin reductase is a [4FE-4S] protein present in organisms performing oxygenic photosynthesis, and plays an important role in the ferredoxin/thioredoxin regulatory chain. It converts an electron signal (photoreduced ferredoxin) to a thiol signal (reduced thioredoxin), regulating enzymes by reduction of specific disulphide groups. It catalyses the light-dependent activation of several photosynthetis enzymes. Ferredoxin thioredoxin reductase is a heterodimer of subunit alpha and subunit beta. Subunit alpha is the variable subunit, and beta is the catalytic chain [ 1 ].

The structure of the beta subunit has been determined and found to fold around the FeS cluster [ 2 ].

1. Amino acid sequence of spinach ferredoxin:thioredoxin reductase catalytic subunit and identification of thiol groups constituting a redox-active disulfide and a [4Fe-4S] cluster. Eur. J. Biochem. 231, 149-56
2. Redox signaling in chloroplasts: cleavage of disulfides by an iron-sulfur cluster. Science 287, 655-8