It is involved in the activation of genes necessary for anaerobic respiration. It probably also activates genes involved in the production of virulence factors. Binds 1 [4Fe-4S] cluster per subunit. Homodimer. By anaerobiosis. The DNA coding for this protein is not found in the complete genome of strain ATCC 27872 / DSM 7271 / JCM 12966 / VPI 2845.