Cholesterol side-chain cleavage enzyme, mitochondrial (EC 1.14.15.6) (CYPXIA1) (Cholesterol desmolase) (Cytochrome P450 11A1) (Cytochrome P450(scc))
1_MLAKG 6_ LPPRS 11_ VLVKG 16_ CQTFL 21_ SAPRE 26_ GLGRL 31_ RVPTG 36_ EGAGI 41_ STRSP 46_ RPFNE 51_ IPSPG 56_ DNGWL 61_ NLYHF 66_ WRETG 71_ THKVH 76_ LHHVQ 81_ NFQKY 86_ GPIYR 91_ EKLGN 96_ VESVY 101_ VIDPE 106_ DVALL 111_ FKSEG 116_ PNPER 121_ FLIPP 126_ WVAYH 131_ QYYQR 136_ PIGVL 141_ LKKSA 146_ AWKKD 151_ RVALN 156_ QEVMA 161_ PEATK 166_ NFLPL 171_ LDAVS 176_ RDFVS 181_ VLHRR 186_ IKKAG 191_ SGNYS 196_ GDISD 201_ DLFRF 206_ AFESI 211_ TNVIF 216_ GERQG 221_ MLEEV 226_ VNPEA 231_ QRFID 236_ AIYQM 241_ FHTSV 246_ PMLNL 251_ PPDLF 256_ RLFRT 261_ KTWKD 266_ HVAAW 271_ DVIFS 276_ KADIY 281_ TQNFY 286_ WELRQ 291_ KGSVH 296_ HDYRG 301_ ILYRL 306_ LGDSK 311_ MSFED 316_ IKANV 321_ TEMLA 326_ GGVDT 331_ TSMTL 336_ QWHLY 341_ EMARN 346_ LKVQD 351_ MLRAE 356_ VLAAR 361_ HQAQG 366_ DMATM 371_ LQLVP 376_ LLKAS 381_ IKETL 386_ RLHPI 391_ SVTLQ 396_ RYLVN 401_ DLVLR 406_ DYMIP 411_ AKTLV 416_ QVAIY 421_ ALGRE 426_ PTFFF 431_ DPENF 436_ DPTRW 441_ LSKDK 446_ NITYF 451_ RNLGF 456_ GWGVR 461_ QCLGR 466_ RIAEL 471_ EMTIF 476_ LINML 481_ ENFRV 486_ EIQHL 491_ SDVGT 496_ TFNLI 501_ LMPEK 506_ PISFT 511_ FWPFN 516_QEATQ
1: A cytochrome P450 monooxygenase that catalyzes the side-chain hydroxylation and cleavage of cholesterol to pregnenolone, the precursor of most steroid hormones (PubMed:21636783). Catalyzes three sequential oxidation reactions of cholesterol, namely the hydroxylation at C22 followed with the hydroxylation at C20 to yield 20R,22R-hydroxycholesterol that is further cleaved between C20 and C22 to yield the C21-steroid pregnenolone and 4-methylpentanal (PubMed:21636783). Mechanistically, uses molecular oxygen inserting one oxygen atom into a substrate and reducing the second into a water molecule. Two electrons are provided by NADPH via a two-protein mitochondrial transfer system comprising flavoprotein FDXR (adrenodoxin/ferredoxin reductase) and nonheme iron-sulfur protein FDX1 or FDX2 (adrenodoxin/ferredoxin) (PubMed:21636783)