The apo- but not holo-form probably binds DNA (By similarity). Acts as a transcriptional regulator. Probably redox-responsive. Upon overproduction at least 10 other genes are up-regulated, among them are Rv1258c, Rv1988, Rv2301, Rv2416c, Rv2725c and whiB7 itself. Probably redox-responsive. The apo-form has been shown to act as a protein disulfide reductase. Binds 1 [4Fe-4S] cluster per subunit. Contains 1 [2Fe-2S] cluster after reconstitution of overexpressed protein from E.coli. Following nitrosylation of the [4Fe-4S] cluster binds 1 [4Fe-8(NO)] cluster per subunit. By sublethal doses of antibiotics such as erythromycin, streptomycin and tetracycline as well as the fatty acids palmitic and oleic acid (in clinical strain 1254). By the antibiotic erythromycin. Positively regulates its own expression (in strain H37Rv). The Fe-S cluster can be nitrosylated by nitric oxide (NO). Upon Fe-S cluster removal intramolecular disulfide bonds are formed. Fully oxidized recombinant protein tagged at both termini. Fully reduced recombinant protein tagged at both termini. Decreased resistance to macrolides, a lincosamide, and an aminoglycoside antibiotic. Belongs to the WhiB family.