cyp27a1 cyp27a1 cyp27a1 is a gene encoding a cytochrome p450 oxidase, and is commonly known as sterol 27-hydroxylase. this enzyme is located in many different tissues where it is found within the mitochondria. it is most prominently involved in the biosynthesis of bile acids. cyp27a1available structurespdbortholog search: pdbe rcsb list of pdb id codes1mfxidentifiersaliasescyp27a1, cp27, ctx, cyp27, cytochrome p450 family 27 subfamily a member 1external idsomim: 606530 mgi: 88594 homologene: 36040 genecards: cyp27a1 gene location (human)chr.chromosome 2 (human)band2q35start218,781,749 bpend218,815,293 bpgene location (mouse)chr.chromosome 1 (mouse)band1 c4|1 38.54 cmstart74,752,733 bpend74,777,051 bprna expression patternbgeehumanmouse (ortholog)top expressed inright lobe of livertibial nerveleft adrenal glandupper lobe of left lungright uterine tubeduodenummonocyteright lunginferior ganglion of vagus nervejejunal mucosatop expressed inleft lobe of liveresophagusskeletal muscle tissuetriceps brachii muscletemporal muscletibialis anterior musclevastus lateralis muscledigastric musclesternocleidomastoid musclemasseter musclemore reference expression databiogpsmore reference expression datagene ontologymolecular function monooxygenase activity iron ion binding steroid hydroxylase activity oxidoreductase activity heme binding oxidoreductase activity, acting on paired donors, with incorporation or reduction of molecular oxygen metal ion binding vitamin d3 25-hydroxylase activity cholesterol 26-hydroxylase activity cholestanetriol 26-monooxygenase activity cellular component mitochondrial matrix membrane mitochondrial membrane mitochondrion mitochondrial inner membrane biological process sterol metabolic process bile acid biosynthetic process cholesterol catabolic process calcitriol biosynthetic process from calciol lipid metabolism steroid biosynthetic process steroid metabolic process cholesterol metabolic process sources:amigo / quickgoorthologsspecieshumanmouseentrez1593104086ensemblensg00000135929ensmusg00000026170uniprotq02318q9dbg1refseq (mrna)nm_000784nm_024264refseq (protein)np_000775np_077226location (ucsc)chr 2: 218.78 – 218.82 mbchr 1: 74.75 – 74.78 mbpubmed searchwikidataview/edit humanview/edit mouse function cyp27a1 participates in the degradation of cholesterol to bile acids in both the classic and acidic pathways. it is the initiating enzyme in the acidic pathway to bile acids, yielding oxysterols by introducing a hydroxyl group to the carbon at the 27 position in cholesterol. in the acidic pathway, it produces 27-hydroxycholesterol from cholesterol whereas in the classic or neutral pathway, it produces 3β-hydroxy-5-cholestenoic acid. while cyp27a1 is present in many different tissues, its function in these tissues is largely uncharacterized. in macrophages, 27-hydroxycholesterol generated by this enzyme may be helpful against the production of inflammatory factors associated with cardiovascular disease. clinical significance mutations in cyp27a1 are associated with cerebrotendineous xanthomatosis, a rare lipid storage disease. inhibitors of cyp27a1 may be effective as adjuvants in the treatment of er-positive breast cancer due to inhibition of the production of 27-hydroxycholesterol (which has estrogenic actions and stimulates the growth of er-positive breast cancer cells). some marketed drugs that have been identified as cyp27a1 inhibitors include anastrozole, fadrozole, bicalutamide, dexmedetomidine, ravuconazole, and posaconazole. interactive pathway map click on genes, proteins and metabolites below to link to respective articles. [[file: |alt=vitamin d synthesis pathway (view / edit)]] vitamin d synthesis pathway (view / edit) the interactive pathway map can be edited at wikipathways: "vitamindsynthesis_wp1531".