Cytochrome P450 7B1 (24-hydroxycholesterol 7-alpha-hydroxylase) (EC 1.14.14.26) (25/26-hydroxycholesterol 7-alpha-hydroxylase) (EC 1.14.14.29) (3-hydroxysteroid 7-alpha hydroxylase) (Oxysterol 7-alpha-hydroxylase)
1_MAGEV 6_ SAATG 11_ RFSLE 16_ RLGLP 21_ GLALA 26_ AALLL 31_ LALCL 36_ LVRRT 41_ RRPGE 46_ PPLIK 51_ GWLPY 56_ LGVVL 61_ NLRKD 66_ PLRFM 71_ KTLQK 76_ QHGDT 81_ FTVLL 86_ GGKYI 91_ TFILD 96_ PFQYQ 101_ LVIKN 106_ HKQLS 111_ FRVFS 116_ NKLLE 121_ KAFSI 126_ SQLQK 131_ NHDMN 136_ DELHL 141_ CYQFL 146_ QGKSL 151_ DILLE 156_ SMMQN 161_ LKQVF 166_ EPQLL 171_ KTTSW 176_ DTAEL 181_ YPFCS 186_ SIIFE 191_ ITFTT 196_ IYGKV 201_ IVCDN 206_ NKFIS 211_ ELRDD 216_ FLKFD 221_ DKFAY 226_ LVSNI 231_ PIELL 236_ GNVKS 241_ IREKI 246_ IKCFS 251_ SEKLA 256_ KMQGW 261_ SEVFQ 266_ SRQDV 271_ LEKYY 276_ VHEDL 281_ EIGAH 286_ HLGFL 291_ WASVA 296_ NTIPT 301_ MFWAM 306_ YYLLR 311_ HPEAM 316_ AAVRD 321_ EIDRL 326_ LQSTG 331_ QKKGS 336_ GFPIH 341_ LTREQ 346_ LDSLI 351_ CLESS 356_ IFEAL 361_ RLSSY 366_ STTIR 371_ FVEED 376_ LTLSS 381_ ETGDY 386_ CVRKG 391_ DLVAI 396_ FPPVL 401_ HGDPE 406_ IFEAP 411_ EEFRY 416_ DRFIE 421_ DGKKK 426_ TTFFK 431_ RGKKL 436_ KCYLM 441_ PFGTG 446_ TSKCP 451_ GRFFA 456_ LMEIK 461_ QLLVI 466_ LLTYF 471_ DLEII 476_ DDKPI 481_ GLNYS 486_ RLLFG 491_ IQYPD 496_ SDVLF 501_RYKVK
1: A cytochrome P450 monooxygenase involved in the metabolism of endogenous oxysterols and steroid hormones, including neurosteroids (PubMed:10588945, PubMed:24491228). Mechanistically, uses molecular oxygen inserting one oxygen atom into a substrate, and reducing the second into a water molecule, with two electrons provided by NADPH via cytochrome P450 reductase (CPR; NADPH-ferrihemoprotein reductase) (PubMed:10588945, PubMed:24491228). Catalyzes the hydroxylation of carbon hydrogen bonds of steroids with a preference for 7-alpha position (PubMed:10588945, PubMed:24491228). Usually metabolizes steroids carrying a hydroxy group at position 3, functioning as a 3-hydroxy steroid 7-alpha hydroxylase (PubMed:24491228). Hydroxylates oxysterols, including 25-hydroxycholesterol and (25R)-cholest-5-ene-3beta,26-diol toward 7-alpha hydroxy derivatives, which may be transported to the liver and converted to bile acids (PubMed:10588945, PubMed:9802883). Via its product 7-alpha,25-dihydroxycholesterol, a ligand for the chemotactic G protein-coupled receptor GPR183/EBI2, regulates B cell migration in germinal centers of lymphoid organs, thus guiding efficient maturation of plasma B cells and overall antigen-specific humoral immune response (By similarity). 7-alpha hydroxylates neurosteroids, including 3beta-hydroxyandrost-5-en-17-one (dehydroepiandrosterone) and pregnenolone, both involved in hippocampus-associated memory and learning (PubMed:24491228). Metabolizes androstanoids toward 6- or 7-alpha hydroxy derivatives (PubMed:24491228)