Endogenous retrovirus group K member 21 Env polyprotein (EnvK1 protein) (Envelope polyprotein) (HERV-K_12q14.1 provirus ancestral Env polyprotein) [Cleaved into: Surface protein (SU); Transmembrane protein (TM)]
1_MHPSE 6_ MQRKA 11_ PPRRR 16_ RHRNR 21_ APLTH 26_ KMNKM 31_ VTSEQ 36_ MKLPS 41_ TKKAE 46_ PPTWA 51_ QLKKL 56_ TQLAT 61_ KYLEN 66_ TKVTQ 71_ TPESM 76_ LLAAL 81_ MIVSM 86_ VVSLP 91_ MPAGA 96_ AAANY 101_ TNWAY 106_ VPFPP 111_ LIRAV 116_ TWMDN 121_ PIEVY 126_ VNDSV 131_ WVHGP 136_ IDDRC 141_ PAKPE 146_ EEGMM 151_ INISI 156_ GYHYP 161_ PICLG 166_ RAPGC 171_ LMPAV 176_ QNWLV 181_ EVPTV 186_ SPISR 191_ FTYNM 196_ VSGMS 201_ LRPRV 206_ NYLQD 211_ FSYQR 216_ SLKFR 221_ PKGKP 226_ CPKEI 231_ PKESK 236_ NTEVL 241_ VWEEC 246_ VANSV 251_ VILQN 256_ NEFGT 261_ IIDWA 266_ PRGQF 271_ YHNCS 276_ GQTQS 281_ CPSAQ 286_ VSPAV 291_ DSDLT 296_ ESLDK 301_ HKHKK 306_ LQSFY 311_ PWEWG 316_ EKGIS 321_ TPRPK 326_ IISPV 331_ SGPEH 336_ PELWR 341_ LTVAS 346_ HHIRI 351_ WSGNQ 356_ TLETR 361_ DRKPF 366_ YTVDL 371_ NSSLT 376_ VPLQS 381_ CVKPP 386_ YMLVV 391_ GNIVI 396_ KPDSQ 401_ TITCE 406_ NCRLL 411_ TCIDS 416_ TFNWQ 421_ HRILL 426_ VRARE 431_ GVWIP 436_ VSMDR 441_ PWEAS 446_ PSIHI 451_ LTEVL 456_ KGVLN 461_ RSKRF 466_ IFTLI 471_ AVIMG 476_ LIAVT 481_ AMAAV 486_ AGVAL 491_ HSFVQ 496_ SVNFV 501_ NDWQK 506_ NSTRL 511_ WNSQS 516_ SIDQK 521_ LANQI 526_ NDLRQ 531_ TVIWM 536_ GDRLM 541_ SLEHR 546_ FQLQC 551_ DWNTS 556_ DFCIT 561_ PQIYN 566_ ESEHH 571_ WDMVR 576_ RHLQG 581_ REDNL 586_ TLDIS 591_ KLKEQ 596_ IFEAS 601_ KAHLN 606_ LVPGT 611_ EAIAG 616_ VADGL 621_ ANLNP 626_ VTWVK 631_ TIGST 636_ TIINL 641_ ILILV 646_ CLFCL 651_ LLVCR 656_ CTQQL 661_ RRDSD 666_ HRERA 671_ MMTMV 676_ VLSKR 681_ KGGNV 686_ GKSKR 691_DQIVT
1: Retroviral envelope proteins mediate receptor recognition and membrane fusion during early infection. Endogenous envelope proteins may have kept, lost or modified their original function during evolution. This endogenous envelope protein has lost its original fusogenic properties
2: SU mediates receptor recognition
3: TM anchors the envelope heterodimer to the viral membrane through one transmembrane domain. The other hydrophobic domain, called fusion peptide, mediates fusion of the viral membrane with the target cell membrane (By similarity)