Function
Probably involved in the degradation of cholesterol. In vitro, catalyzes the introduction of a 9alpha-hydroxyl moiety into the ring B of 3-ketosteroid substrates such as 1,4-androstadiene-3,17-dione (ADD), 4-androstene-3,17-dione (AD), 4-androstene-17beta-ol-3-one (testosterone), 4-pregnene-3,20-dione (progesterone), 19-nor-4-androstene-3,17-dione (nordion), 1-(5alpha)-androstene-3,17-dione, 5alpha-androstane-3,17-dione and 5beta-androstane-3,17-dione. KSH has the highest activity with 3-keto-Delta4 steroid substrates.
Sequence
MTTVEVPHGSRSVILTVSAVVEETADTRSIVFAVPDELRDKFAYRPGQFLTLRIPSDRTGSVARCYSLASSPFTDDAPKVTVKRTSDGYGSNWLCDNIATGQTLEVLPPAGVFTPKSLDHDFLLFGAGSGITPVISILKSALTQGGGKVVLVYANRDEKSVIFAEELRALAEKYPTRLTVVHWLESVQGLPTADQLAAIAAPYESYEAFMCGPGPFMDTVHQALNTVGMPRARVHAEVFNSLSGDPFADQAPVEVSDEDAADAATVEVELDGEVHKLSWPRKQTLVDIMLAKGIDVPYSCQEGECGSCACTVLEGKVEMENCDVLDPEDIEAGYILGCQARPVTDHLKIEF