ID   ENV_MLVAV               Reviewed;         669 AA.
AC   P03386;
DT   21-JUL-1986, integrated into UniProtKB/Swiss-Prot.
DT   21-JUL-1986, sequence version 1.
DT   10-JUN-2026, entry version 128.
DE   RecName: Full=Envelope glycoprotein;
DE   AltName: Full=Env polyprotein;
DE   Contains:
DE     RecName: Full=Surface protein;
DE              Short=SU;
DE     AltName: Full=Glycoprotein 70;
DE              Short=gp70;
DE   Contains:
DE     RecName: Full=Transmembrane protein;
DE              Short=TM;
DE     AltName: Full=Envelope protein p15E;
DE   Contains:
DE     RecName: Full=R-peptide;
DE     AltName: Full=p2E;
DE   Flags: Precursor;
GN   Name=env;
OS   AKV murine leukemia virus (AKR (endogenous) murine leukemia virus).
OC   Viruses; Riboviria; Pararnavirae; Artverviricota; Revtraviricetes;
OC   Ortervirales; Retroviridae; Orthoretrovirinae; Gammaretrovirus;
OC   Gammaretrovirus murleu; Murine leukemia virus.
OX   NCBI_TaxID=11791;
OH   NCBI_TaxID=10090; Mus musculus (Mouse).
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC RNA].
RX   PubMed=6319746; DOI=10.1128/jvi.49.2.471-478.1984;
RA   Herr W.;
RT   "Nucleotide sequence of AKV murine leukemia virus.";
RL   J. Virol. 49:471-478(1984).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [GENOMIC RNA].
RX   PubMed=6294621; DOI=10.1093/nar/10.21.6931;
RA   Herr W., Corbin V., Gilbert W.;
RT   "Nucleotide sequence of the 3' half of AKV.";
RL   Nucleic Acids Res. 10:6931-6944(1982).
RN   [3]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=6283170; DOI=10.1128/jvi.42.2.519-529.1982;
RA   Lenz J., Crowther R., Straceski A., Haseltine W.;
RT   "Nucleotide sequence of the Akv env gene.";
RL   J. Virol. 42:519-529(1982).
CC   -!- FUNCTION: The surface protein (SU) attaches the virus to the host cell
CC       by binding to its receptor. This interaction triggers the refolding of
CC       the transmembrane protein (TM) and is thought to activate its fusogenic
CC       potential by unmasking its fusion peptide. Fusion occurs at the host
CC       cell plasma membrane (By similarity). {ECO:0000250}.
CC   -!- FUNCTION: The transmembrane protein (TM) acts as a class I viral fusion
CC       protein. Under the current model, the protein has at least 3
CC       conformational states: pre-fusion native state, pre-hairpin
CC       intermediate state, and post-fusion hairpin state. During viral and
CC       target cell membrane fusion, the coiled coil regions (heptad repeats)
CC       assume a trimer-of-hairpins structure, positioning the fusion peptide
CC       in close proximity to the C-terminal region of the ectodomain. The
CC       formation of this structure appears to drive apposition and subsequent
CC       fusion of viral and target cell membranes. Membranes fusion leads to
CC       delivery of the nucleocapsid into the cytoplasm (By similarity).
CC       {ECO:0000250}.
CC   -!- SUBUNIT: The mature envelope protein (Env) consists of a trimer of SU-
CC       TM heterodimers attached by a labile interchain disulfide bond.
CC       {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: [Transmembrane protein]: Virion membrane
CC       {ECO:0000250}; Single-pass type I membrane protein {ECO:0000250}. Host
CC       cell membrane {ECO:0000250}; Single-pass type I membrane protein
CC       {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: [Surface protein]: Virion membrane; Peripheral
CC       membrane protein. Host cell membrane {ECO:0000250}; Peripheral membrane
CC       protein {ECO:0000250}. Note=The surface protein is not anchored to the
CC       viral envelope, but associates with the virion surface through its
CC       binding to TM. Both proteins are thought to be concentrated at the site
CC       of budding and incorporated into the virions possibly by contacts
CC       between the cytoplasmic tail of Env and the N-terminus of Gag (By
CC       similarity). {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: [R-peptide]: Host cell membrane {ECO:0000250};
CC       Peripheral membrane protein {ECO:0000250}. Note=The R-peptide is
CC       membrane-associated through its palmitate. {ECO:0000250}.
CC   -!- DOMAIN: The YXXL motif is involved in determining the exact site of
CC       viral release at the surface of infected mononuclear cells and promotes
CC       endocytosis.
CC   -!- DOMAIN: The 17 amino acids long immunosuppressive region is present in
CC       many retroviral envelope proteins. Synthetic peptides derived from this
CC       relatively conserved sequence inhibit immune function in vitro and in
CC       vivo (By similarity). {ECO:0000250}.
CC   -!- PTM: Specific enzymatic cleavages in vivo yield mature proteins.
CC       Envelope glycoproteins are synthesized as an inactive precursor that is
CC       N-glycosylated and processed likely by host cell furin or by a furin-
CC       like protease in the Golgi to yield the mature SU and TM proteins. The
CC       cleavage site between SU and TM requires the minimal sequence [KR]-X-
CC       [KR]-R. The R-peptide is released from the C-terminus of the
CC       cytoplasmic tail of the TM protein upon particle formation as a result
CC       of proteolytic cleavage by the viral protease. Cleavage of this peptide
CC       is required for TM to become fusogenic (By similarity). {ECO:0000250}.
CC   -!- PTM: The CXXC motif is highly conserved across a broad range of
CC       retroviral envelope proteins. It is thought to participate in the
CC       formation of a labile disulfide bond possibly with the CX6CC motif
CC       present in the transmembrane protein. Isomerization of the intersubunit
CC       disulfide bond to an SU intrachain disulfide bond is thought to occur
CC       upon receptor recognition in order to allow membrane fusion (By
CC       similarity). {ECO:0000250}.
CC   -!- PTM: The transmembrane protein is palmitoylated. {ECO:0000250}.
CC   -!- PTM: The R-peptide is palmitoylated. {ECO:0000250}.
CC   -!- SEQUENCE CAUTION:
CC       Sequence=CAA24493.1; Type=Erroneous initiation; Evidence={ECO:0000305};
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DR   EMBL; J01998; AAB03092.1; -; Genomic_RNA.
DR   EMBL; V01164; CAA24493.1; ALT_INIT; Genomic_DNA.
DR   PIR; A92995; VCVWEK.
DR   SMR; P03386; -.
DR   GlyCosmos; P03386; 7 sites, No reported glycans.
DR   GO; GO:0020002; C:host cell plasma membrane; IEA:UniProtKB-SubCell.
DR   GO; GO:0019031; C:viral envelope; IEA:UniProtKB-KW.
DR   GO; GO:0055036; C:virion membrane; IEA:UniProtKB-SubCell.
DR   GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR   GO; GO:0019064; P:fusion of virus membrane with host plasma membrane; IEA:UniProtKB-KW.
DR   GO; GO:0046718; P:symbiont entry into host cell; IEA:UniProtKB-KW.
DR   GO; GO:0019062; P:virion attachment to host cell; IEA:UniProtKB-KW.
DR   CDD; cd09851; HTLV-1-like_HR1-HR2; 1.
DR   FunFam; 1.10.287.210:FF:000005; Envelope glycoprotein; 1.
DR   Gene3D; 1.10.287.210; -; 1.
DR   Gene3D; 3.90.310.10; ENV polyprotein, receptor-binding domain; 1.
DR   InterPro; IPR008981; FMuLV_rcpt-bd.
DR   InterPro; IPR018154; TLV/ENV_coat_polyprotein.
DR   PANTHER; PTHR10424:SF72; BC035947 PROTEIN-RELATED; 1.
DR   PANTHER; PTHR10424; VIRAL ENVELOPE PROTEIN; 1.
DR   Pfam; PF00429; TLV_coat; 1.
DR   SUPFAM; SSF49830; ENV polyprotein, receptor-binding domain; 1.
DR   SUPFAM; SSF58069; Virus ectodomain; 1.
PE   1: Evidence at protein level;
KW   Cleavage on pair of basic residues; Coiled coil; Disulfide bond;
KW   Fusion of virus membrane with host cell membrane;
KW   Fusion of virus membrane with host membrane; Glycoprotein;
KW   Host cell membrane; Host membrane; Host-virus interaction; Lipoprotein;
KW   Membrane; Metal-binding; Palmitate; Signal; Transmembrane;
KW   Transmembrane helix; Viral attachment to host cell; Viral envelope protein;
KW   Viral penetration into host cytoplasm; Virion; Virus entry into host cell;
KW   Zinc.
FT   SIGNAL          1..31
FT                   /evidence="ECO:0000255"
FT   CHAIN           32..669
FT                   /note="Envelope glycoprotein"
FT                   /id="PRO_0000239579"
FT   CHAIN           32..470
FT                   /note="Surface protein"
FT                   /evidence="ECO:0000250"
FT                   /id="PRO_0000040745"
FT   CHAIN           471..650
FT                   /note="Transmembrane protein"
FT                   /evidence="ECO:0000250"
FT                   /id="PRO_0000040746"
FT   PEPTIDE         651..669
FT                   /note="R-peptide"
FT                   /evidence="ECO:0000250"
FT                   /id="PRO_0000040747"
FT   TOPO_DOM        32..611
FT                   /note="Extracellular"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        612..632
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TOPO_DOM        633..669
FT                   /note="Cytoplasmic"
FT                   /evidence="ECO:0000255"
FT   REGION          32..267
FT                   /note="Receptor-binding domain (RBD)"
FT                   /evidence="ECO:0000255"
FT   REGION          266..310
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   REGION          473..493
FT                   /note="Fusion peptide"
FT                   /evidence="ECO:0000250"
FT   REGION          539..555
FT                   /note="Immunosuppression"
FT                   /evidence="ECO:0000250"
FT   COILED          502..538
FT                   /evidence="ECO:0000255"
FT   MOTIF           337..340
FT                   /note="CXXC"
FT   MOTIF           556..564
FT                   /note="CX6CC"
FT   MOTIF           656..659
FT                   /note="YXXL motif; contains endocytosis signal"
FT                   /evidence="ECO:0000250"
FT   BINDING         117
FT                   /ligand="Zn(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29105"
FT                   /evidence="ECO:0000250"
FT   SITE            470..471
FT                   /note="Cleavage; by host"
FT                   /evidence="ECO:0000250"
FT   SITE            650..651
FT                   /note="Cleavage; by viral protease p14"
FT                   /evidence="ECO:0000250"
FT   LIPID           631
FT                   /note="S-palmitoyl cysteine; by host"
FT                   /evidence="ECO:0000250"
FT   CARBOHYD        43
FT                   /note="N-linked (GlcNAc...) asparagine; by host"
FT                   /evidence="ECO:0000250"
FT   CARBOHYD        199
FT                   /note="N-linked (GlcNAc...) asparagine; by host"
FT                   /evidence="ECO:0000250"
FT   CARBOHYD        293
FT                   /note="N-linked (GlcNAc...) asparagine; by host"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        327
FT                   /note="N-linked (GlcNAc...) asparagine; by host"
FT                   /evidence="ECO:0000250"
FT   CARBOHYD        359
FT                   /note="N-linked (GlcNAc...) asparagine; by host"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        366
FT                   /note="N-linked (GlcNAc...) asparagine; by host"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        399
FT                   /note="N-linked (GlcNAc...) asparagine; by host"
FT                   /evidence="ECO:0000255"
FT   DISULFID        77..129
FT                   /evidence="ECO:0000250"
FT   DISULFID        103..118
FT                   /evidence="ECO:0000250"
FT   DISULFID        104..114
FT                   /evidence="ECO:0000250"
FT   DISULFID        152..172
FT                   /evidence="ECO:0000250"
FT   DISULFID        164..177
FT                   /evidence="ECO:0000250"
FT   DISULFID        209..215
FT                   /evidence="ECO:0000250"
FT   DISULFID        337..564
FT                   /note="Interchain (between SU and TM chains, or C-340 with
FT                   C-564); in linked form"
FT   DISULFID        337..340
FT   DISULFID        367..421
FT                   /evidence="ECO:0000250"
FT   DISULFID        386..398
FT                   /evidence="ECO:0000250"
FT   DISULFID        428..441
FT                   /evidence="ECO:0000250"
FT   DISULFID        556..563
FT                   /evidence="ECO:0000250"
FT   CONFLICT        35
FT                   /note="G -> R (in Ref. 2)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        463
FT                   /note="E -> K (in Ref. 2)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        592
FT                   /note="E -> K (in Ref. 2)"
FT                   /evidence="ECO:0000305"
SQ   SEQUENCE   669 AA;  73756 MW;  3A6C3845208A13F2 CRC64;
     MESTTLSKPF KNQVNPWGPL IVLLILGGVN PVTLGNSPHQ VFNLTWEVTN GDRETVWAIT
     GNHPLWTWWP DLTPDLCMLA LHGPSYWGLE YRAPFSPPPG PPCCSGSSDS TPGCSRDCEE
     PLTSYTPRCN TAWNRLKLSK VTHAHNGGFY VCPGPHRPRW ARSCGGPESF YCASWGCETT
     GRASWKPSSS WDYITVSNNL TSDQATPVCK GNEWCNSLTI RFTSFGKQAT SWVTGHWWGL
     RLYVSGHDPG LIFGIRLKIT DSGPRVPIGP NPVLSDRRPP SRPRPTRSPP PSNSTPTETP
     LTLPEPPPAG VENRLLNLVK GAYQALNLTS PDKTQECWLC LVSGPPYYEG VAVLGTYSNH
     TSAPANCSVA SQHKLTLSEV TGQGLCIGAV PKTHQVLCNT TQKTSDGSYY LAAPTGTTWA
     CSTGLTPCIS TTILDLTTDY CVLVELWPRV TYHSPSYVYH QFERRAKYKR EPVSLTLALL
     LGGLTMGGIA AGVGTGTTAL VATQQFQQLQ AAMHDDLKEV EKSITNLEKS LTSLSEVVLQ
     NRRGLDLLFL KEGGLCAALK EECCFYADHT GLVRDSMAKL RERLSQRQKL FESQQGWFEG
     LFNKSPWFTT LISTIMGPLI ILLLILLFGP CILNRLVQFI KDRISVVQAL VLTQQYHQLK
     TIEDCKSRE
//