Steroid 17-alpha-hydroxylase/17,20 lyase (EC 1.14.14.19) (17-alpha-hydroxyprogesterone aldolase) (EC 1.14.14.32) (CYPXVII) (Cytochrome P450 17A1) (Cytochrome P450-C17) (Cytochrome P450c17) (Steroid 17-alpha-monooxygenase)
1_MWELV 6_ ALLLL 11_ TLAYL 16_ FWPKR 21_ RCPGA 26_ KYPKS 31_ LLSLP 36_ LVGSL 41_ PFLPR 46_ HGHMH 51_ NNFFK 56_ LQKKY 61_ GPIYS 66_ VRMGT 71_ KTTVI 76_ VGHHQ 81_ LAKEV 86_ LIKKG 91_ KDFSG 96_ RPQMA 101_ TLDIA 106_ SNNRK 111_ GIAFA 116_ DSGAH 121_ WQLHR 126_ RLAMA 131_ TFALF 136_ KDGDQ 141_ KLEKI 146_ ICQEI 151_ STLCD 156_ MLATH 161_ NGQSI 166_ DISFP 171_ VFVAV 176_ TNVIS 181_ LICFN 186_ TSYKN 191_ GDPEL 196_ NVIQN 201_ YNEGI 206_ IDNLS 211_ KDSLV 216_ DLVPW 221_ LKIFP 226_ NKTLE 231_ KLKSH 236_ VKIRN 241_ DLLNK 246_ ILENY 251_ KEKFR 256_ SDSIT 261_ NMLDT 266_ LMQAK 271_ MNSDN 276_ GNAGP 281_ DQDSE 286_ LLSDN 291_ HILTT 296_ IGDIF 301_ GAGVE 306_ TTTSV 311_ VKWTL 316_ AFLLH 321_ NPQVK 326_ KKLYE 331_ EIDQN 336_ VGFSR 341_ TPTIS 346_ DRNRL 351_ LLLEA 356_ TIREV 361_ LRLRP 366_ VAPML 371_ IPHKA 376_ NVDSS 381_ IGEFA 386_ VDKGT 391_ EVIIN 396_ LWALH 401_ HNEKE 406_ WHQPD 411_ QFMPE 416_ RFLNP 421_ AGTQL 426_ ISPSV 431_ SYLPF 436_ GAGPR 441_ SCIGE 446_ ILARQ 451_ ELFLI 456_ MAWLL 461_ QRFDL 466_ EVPDD 471_ GQLPS 476_ LEGIP 481_ KVVFL 486_ IDSFK 491_ VKIKV 496_ RQAWR 501_EAQAE
1: A cytochrome P450 monooxygenase involved in corticoid and androgen biosynthesis (PubMed:22266943, PubMed:25301938, PubMed:27339894, PubMed:9452426). Catalyzes 17-alpha hydroxylation of C21 steroids, which is common for both pathways. A second oxidative step, required only for androgen synthesis, involves an acyl-carbon cleavage. The 17-alpha hydroxy intermediates, as part of adrenal glucocorticoids biosynthesis pathway, are precursors of cortisol (Probable) (PubMed:25301938, PubMed:9452426). Hydroxylates steroid hormones, pregnenolone and progesterone to form 17-alpha hydroxy metabolites, followed by the cleavage of the C17-C20 bond to form C19 steroids, dehydroepiandrosterone (DHEA) and androstenedione (PubMed:22266943, PubMed:25301938, PubMed:27339894, PubMed:36640554, PubMed:9452426). Has 16-alpha hydroxylase activity. Catalyzes 16-alpha hydroxylation of 17-alpha hydroxy pregnenolone, followed by the cleavage of the C17-C20 bond to form 16-alpha-hydroxy DHEA (PubMed:36640554). Also 16-alpha hydroxylates androgens, relevant for estriol synthesis (PubMed:25301938, PubMed:27339894). 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:22266943, PubMed:25301938, PubMed:27339894, PubMed:9452426)