This protein seems to be a 2Fe-2S ferredoxin. This dioxygenase system consists of four proteins: the two subunits of the hydroxylase component (BphA1 and BphA2), a ferredoxin (BphA3) and a ferredoxin reductase (BphA4). Belongs to the bacterial ring-hydroxylating dioxygenase ferredoxin component family.