An old activity in the cytochrome P450 superfamily (CYP51) and a new storyof drugs and resistance

Cytochrome P450 51 (CYP51) is sterol 14 alpha -demethylase, known also as E rg11p in yeast. First studied in yeast, where it is one of three CYPs in th e genome, it has subsequently gained attention as the only CYP found so far in different kingdoms of life. As such it is central to considerations of CYP evolution. Recent use of CYP51-inhibiting antifungal drugs, such as flu conazole, has also been associated with dramatic CYP51 evolution to numerou s resistant forms in fungal pathogens. CYP51 has also been discovered in my cobacteria where antifungal azoles ha c e effect and might be of value agai nst tuberculosis. Evolutionary and therapeutic aspects of CYP51 studies are discussed.