Amino acid sequences of P450s in the heme-binding region. Shown are an alignment of CYP51 amino acid sequences from humans, rats, S. cerevisiae (S.C.), Sorghum bicolor (S.B.), Mycobacterium tuberculosis (M.T.), and C. albicans (C.A.) and a comparison to the same region in CYP51(R467K) and various mammalian CYP isoforms involved in foreign compound metabolism. The conserved arginine and lysine residues are in boldface.