ID   ENV_MLVCB               Reviewed;         661 AA.
AC   P08360;
DT   01-AUG-1988, integrated into UniProtKB/Swiss-Prot.
DT   01-AUG-1988, sequence version 1.
DT   27-MAR-2024, entry version 116.
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   Cas-Br-E murine leukemia virus.
OC   Viruses; Riboviria; Pararnavirae; Artverviricota; Revtraviricetes;
OC   Ortervirales; Retroviridae; Orthoretrovirinae; Gammaretrovirus;
OC   Murine leukemia virus.
OX   NCBI_TaxID=11792;
OH   NCBI_TaxID=10090; Mus musculus (Mouse).
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=3023680; DOI=10.1128/jvi.60.3.910-919.1986;
RA   Rassart E., Nelbach L., Jolicoeur P.;
RT   "Cas-Br-E murine leukemia virus: sequencing of the paralytogenic region of
RT   its genome and derivation of specific probes to study its origin and the
RT   structure of its recombinant genomes in leukemic tissues.";
RL   J. Virol. 60:910-919(1986).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=1840655; DOI=10.1093/nar/19.7.1707;
RA   Perryman S.M., McAtee F.J., Portis J.L.;
RT   "Complete nucleotide sequence of the neurotropic murine retrovirus CAS-BR-
RT   E.";
RL   Nucleic Acids Res. 19:1707-1707(1991).
RN   [3]
RP   CLEAVAGE OF R-PEPTIDE.
RX   PubMed=12185279; DOI=10.1099/0022-1317-83-9-2241;
RA   Bobkova M., Stitz J., Engelstadter M., Cichutek K., Buchholz C.J.;
RT   "Identification of R-peptides in envelope proteins of C-type
RT   retroviruses.";
RL   J. Gen. Virol. 83:2241-2246(2002).
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}.
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DR   EMBL; M14702; AAA46512.1; -; Genomic_DNA.
DR   EMBL; X57540; -; NOT_ANNOTATED_CDS; Genomic_DNA.
DR   PIR; B26103; VCMVCB.
DR   SMR; P08360; -.
DR   GlyCosmos; P08360; 6 sites, No reported glycans.
DR   GO; GO:0020002; C:host cell plasma membrane; IEA:UniProtKB-SubCell.
DR   GO; GO:0016020; C:membrane; IEA:UniProtKB-KW.
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:viral 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   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:SF77; 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..33
FT                   /evidence="ECO:0000255"
FT   CHAIN           34..661
FT                   /note="Envelope glycoprotein"
FT                   /id="PRO_0000239580"
FT   CHAIN           34..465
FT                   /note="Surface protein"
FT                   /evidence="ECO:0000250"
FT                   /id="PRO_0000040748"
FT   CHAIN           466..645
FT                   /note="Transmembrane protein"
FT                   /evidence="ECO:0000250"
FT                   /id="PRO_0000040749"
FT   PEPTIDE         646..661
FT                   /note="R-peptide"
FT                   /id="PRO_0000040750"
FT   TOPO_DOM        34..606
FT                   /note="Extracellular"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        607..627
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TOPO_DOM        628..661
FT                   /note="Cytoplasmic"
FT                   /evidence="ECO:0000255"
FT   REGION          32..267
FT                   /note="Receptor-binding domain (RBD)"
FT                   /evidence="ECO:0000255"
FT   REGION          268..308
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   REGION          468..488
FT                   /note="Fusion peptide"
FT                   /evidence="ECO:0000250"
FT   REGION          534..550
FT                   /note="Immunosuppression"
FT                   /evidence="ECO:0000250"
FT   COILED          497..533
FT                   /evidence="ECO:0000255"
FT   MOTIF           332..335
FT                   /note="CXXC"
FT   MOTIF           551..559
FT                   /note="CX6CC"
FT   MOTIF           651..654
FT                   /note="YXXL motif; contains endocytosis signal"
FT                   /evidence="ECO:0000250"
FT   COMPBIAS        273..298
FT                   /note="Pro residues"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   BINDING         86
FT                   /ligand="Zn(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29105"
FT                   /evidence="ECO:0000250"
FT   BINDING         117
FT                   /ligand="Zn(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29105"
FT                   /evidence="ECO:0000250"
FT   SITE            465..466
FT                   /note="Cleavage; by host"
FT                   /evidence="ECO:0000250"
FT   SITE            645..646
FT                   /note="Cleavage; by viral protease p14"
FT   LIPID           626
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        322
FT                   /note="N-linked (GlcNAc...) asparagine; by host"
FT                   /evidence="ECO:0000250"
FT   CARBOHYD        361
FT                   /note="N-linked (GlcNAc...) asparagine; by host"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        394
FT                   /note="N-linked (GlcNAc...) asparagine; by host"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        430
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        332..559
FT                   /note="Interchain (between SU and TM chains, or C-335 with
FT                   C-559); in linked form"
FT   DISULFID        332..335
FT   DISULFID        362..416
FT                   /evidence="ECO:0000250"
FT   DISULFID        381..393
FT                   /evidence="ECO:0000250"
FT   DISULFID        423..436
FT                   /evidence="ECO:0000250"
FT   DISULFID        551..558
FT                   /evidence="ECO:0000250"
FT   CONFLICT        476..477
FT                   /note="PE -> LG (in Ref. 2)"
FT                   /evidence="ECO:0000305"
SQ   SEQUENCE   661 AA;  72625 MW;  255BEE3AF62FB9FF CRC64;
     MEGPAFSKSP KDKTIERAFL GVLGILFVTG GLASRDNPHQ VYNITWEVTN GEQDTVWAVT
     GNHPLWTWWP DLTPDLCMLA LHGPTHWGLD NHPPYSSPPG PPCCSGDAGA VSGCARDCDE
     PLTSYSPRCN TAWNRLKLAR VTHAPKEGFY ICPGSHRPRW ARSCGGLDAY YCASWGCETT
     GRAAWNPTSS WDYITVSNNL TSSQATKACK NNGWCNPLVI RFTGPGKRAT SWTTGHFWGL
     RLYISGHDPG LTFGIRLKVT DLGPRVPIGP NPVLSDQRPP SRPVPARPPP PSASPSTPTI
     PPQQGTGDRL LNLVQGAYLT LNMTDPTRTQ ECWLCLVSEP PYYEGVAVLR EYTSHETAPA
     NCSSGSQHKL TLSEVTGQGR CLGTVPKTHQ ALCNRTEPTV SGSNYLVAPE GTLWACSTGL
     TPCLSTTVLN LTTDYCVLVE LWPKVTYHSP DYVYTQFEPG ARFRREPVSL TLALLPEGLT
     MGGIAAGVGT GTTALVATQQ FQQLQAAMHN DLKEVEKSIT NLEKSLTSLS EVVLQNRRGL
     DLLFLKEGGL CAALKEECCF YADHTGLVRD SMAKLRERLN QRQKLFESGQ GWFEGLFNRS
     PWFTTLISTI MGPLIVLLLI LLFGPCILNR LVQFVKDRIS VVQALVLTQQ YHQLKPIEYE
     P
//