Lathosterol oxidase
cholesterol biosynthetic process
cDNA cloning of the mammalian sterol C5-desaturase and the expression in yeast mutant.
Sterol C5-desaturase (SC5D) cDNA is an enzyme that catalyzes the dehydrogenation to introduce C5-6 double bond into lathosterol in cholesterol biosynthesis. We have isolated and sequenced the cDNA clones encoding human and mouse SC5D. The functional complementation of a defective yeast mutant proves that the human and mouse cDNA clones encode SC5D. Mammalian SC5D was presumed as an integral membrane protein containing histidine residues conserved also in yeasts and plant.