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P03388 (ENV_MCFF3) Reviewed, UniProtKB/Swiss-Prot

Last modified February 19, 2014. Version 99. Feed History...

Clusters with 100%, 90%, 50% identity | Third-party data text xml rdf/xml gff fasta
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Names and origin

Protein namesRecommended name:
Envelope glycoprotein
Alternative name(s):
Env polyprotein

Cleaved into the following 3 chains:

  1. Surface protein
    Short name=SU
    Alternative name(s):
    Glycoprotein 70
    Short name=gp70
  2. Transmembrane protein
    Short name=TM
    Alternative name(s):
    Envelope protein p15E
  3. R-peptide
    Alternative name(s):
    p2E
Gene names
Name:env
OrganismMink cell focus-forming murine leukemia virus (isolate CI-3)
Taxonomic identifier11936 [NCBI]
Taxonomic lineageVirusesRetro-transcribing virusesRetroviridaeOrthoretrovirinaeGammaretrovirusMurine leukemia virus
Virus hostMus musculus (Mouse) [TaxID: 10090]

Protein attributes

Sequence length640 AA.
Sequence statusComplete.
Sequence processingThe displayed sequence is further processed into a mature form.
Protein existenceInferred from homology

General annotation (Comments)

Function

The surface protein (SU) attaches the virus to the host cell by binding to its receptor. This interaction triggers the refolding of the transmembrane protein (TM) and is thought to activate its fusogenic potential by unmasking its fusion peptide. Fusion occurs at the host cell plasma membrane By similarity.

The transmembrane protein (TM) acts as a class I viral fusion protein. Under the current model, the protein has at least 3 conformational states: pre-fusion native state, pre-hairpin intermediate state, and post-fusion hairpin state. During viral and target cell membrane fusion, the coiled coil regions (heptad repeats) assume a trimer-of-hairpins structure, positioning the fusion peptide in close proximity to the C-terminal region of the ectodomain. The formation of this structure appears to drive apposition and subsequent fusion of viral and target cell membranes. Membranes fusion leads to delivery of the nucleocapsid into the cytoplasm By similarity.

Subunit structure

The mature envelope protein (Env) consists of a trimer of SU-TM heterodimers attached by a labile interchain disulfide bond By similarity.

Subcellular location

Transmembrane protein: Virion membrane; Single-pass type I membrane protein By similarity. Host cell membrane; Single-pass type I membrane protein By similarity.

Surface protein: Virion membrane; Peripheral membrane protein. Host cell membrane; Peripheral membrane protein By similarity. Note: The surface protein is not anchored to the viral envelope, but associates with the virion surface through its binding to TM. Both proteins are thought to be concentrated at the site of budding and incorporated into the virions possibly by contacts between the cytoplasmic tail of Env and the N-terminus of Gag By similarity.

R-peptide: Host cell membrane; Peripheral membrane protein By similarity. Note: The R-peptide is membrane-associated through its palmitate By similarity.

Domain

The 17 amino acids long immunosuppressive region is present in many retroviral envelope proteins. Synthetic peptides derived from this relatively conserved sequence inhibit immune function in vitro and in vivo By similarity.

The YXXL motif is involved in determining the exact site of viral release at the surface of infected mononuclear cells and promotes endocytosis.

Post-translational modification

Specific enzymatic cleavages in vivo yield mature proteins. Envelope glycoproteins are synthesized as a inactive precursor that is N-glycosylated and processed likely by host cell furin or by a furin-like protease in the Golgi to yield the mature SU and TM proteins. The cleavage site between SU and TM requires the minimal sequence [KR]-X-[KR]-R. The R-peptide is released from the C-terminus of the cytoplasmic tail of the TM protein upon particle formation as a result of proteolytic cleavage by the viral protease. Cleavage of this peptide is required for TM to become fusogenic By similarity.

The CXXC motif is highly conserved across a broad range of retroviral envelope proteins. It is thought to participate in the formation of a labile disulfide bond possibly with the CX6CC motif present in the transmembrane protein. Isomerization of the intersubunit disulfide bond to an SU intrachain disulfide bond is thought to occur upon receptor recognition in order to allow membrane fusion By similarity.

The R-peptide is palmitoylated By similarity.

Miscellaneous

The sequence shown is that of isolate CI-3.

Sequence annotation (Features)

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifier

Molecule processing

Signal peptide1 – 3232 Potential
Chain33 – 640608Envelope glycoprotein
PRO_0000239578
Chain33 – 441409Surface protein By similarity
PRO_0000040742
Chain442 – 621180Transmembrane protein By similarity
PRO_0000040743
Peptide622 – 64019R-peptide By similarity
PRO_0000040744

Regions

Topological domain33 – 582550Extracellular Potential
Transmembrane583 – 60321Helical; Potential
Topological domain604 – 64037Cytoplasmic Potential
Region444 – 46421Fusion peptide By similarity
Region510 – 52617Immunosuppression By similarity
Coiled coil473 – 50937 Potential
Motif307 – 3104CXXC
Motif527 – 5359CX6CC
Motif627 – 6304YXXL motif; contains endocytosis signal By similarity
Compositional bias255 – 2639Poly-Pro

Sites

Site441 – 4422Cleavage; by host By similarity
Site621 – 6222Cleavage; by viral protease p14 By similarity

Amino acid modifications

Glycosylation431N-linked (GlcNAc...); by host By similarity
Glycosylation581N-linked (GlcNAc...); by host Potential
Glycosylation2971N-linked (GlcNAc...); by host By similarity
Glycosylation3291N-linked (GlcNAc...); by host Potential
Glycosylation3361N-linked (GlcNAc...); by host Potential
Glycosylation3691N-linked (GlcNAc...); by host Potential
Disulfide bond109 ↔ 126 By similarity
Disulfide bond118 ↔ 131 By similarity
Disulfide bond307 ↔ 535Interchain (between SU and TM chains, or C-310 with C-535); alternate By similarity
Disulfide bond307 ↔ 310Alternate By similarity
Disulfide bond337 ↔ 391 By similarity
Disulfide bond356 ↔ 368 By similarity
Disulfide bond398 ↔ 411 By similarity
Disulfide bond527 ↔ 534 By similarity

Natural variations

Natural variant315 – 542228Missing in strain: Isolate CI-4.

Sequences

Sequence LengthMass (Da)Tools
P03388 [UniParc].

Last modified July 21, 1986. Version 1.
Checksum: C2C71A6749128CF5

FASTA64069,726
        10         20         30         40         50         60 
MEGPAFSKPL KDKINPWGPL IILGILIRAG VSVQHDSPHQ VFNVTWRVTN LMTGQTANAT 

        70         80         90        100        110        120 
SLLGTMTDAF PKLYFDLCDL VGDDWDETGL GCRTPGGRKR ARTFDFYVCP GHTVPTGCGG 

       130        140        150        160        170        180 
PREGYCGKWG CETTGQAYWK PSSSWDLISL KRGNTPRNQG PCYDSSAVSS DIKGATPGGR 

       190        200        210        220        230        240 
CNPLVLEFTD AGKKASWDGP KVWGLRLYRS TGTDPVTRFS LTRQVLNIGP RVPIGPNPVI 

       250        260        270        280        290        300 
TDQLPPSRPV QIMLPRPPQP PPPGAASIVP ETAPPSQQLG TGDRLLNLVN GAYQALNLTS 

       310        320        330        340        350        360 
PDKTQECWLC LVAGPPYYEG VAVLGTYSNH TSAPANCSVA SQHKLTLSGV AGRGLCIAAF 

       370        380        390        400        410        420 
PKTHQALCNT TQKTSDGSYH LAAPAGTIWA CNTGLTPCLS TTVLDLTTDY CVLVELWPKV 

       430        440        450        460        470        480 
TYHSPSYVYG QFEKKKTKYK REPVSLTLAL LLGGLTMGGI AAGVGTGTTA LVATQQFQQL 

       490        500        510        520        530        540 
QAAMHDDLKE VEKSITNLEK SLTSLSEVVL QNRRGLDLLF LKEGGLCAAL KEECCFYADH 

       550        560        570        580        590        600 
TGLVRDSMAK LRERLSQRQK LFESQQGWFE GLFNKSPWFT TLISTIMGPL IILLLILLFG 

       610        620        630        640 
PWILNRLVQF IKDRISVVQA LVLTQQYHQL KTIGDCKSRE 

« Hide

References

[1]"Envelope gene sequence of two in vitro-generated mink cell focus-forming murine leukemia viruses which contain the entire gp70 sequence of the endogenous nonecotropic parent."
Mark G.E., Rapp U.R.
J. Virol. 49:530-539(1984) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC RNA].
Strain: Isolate CI-3 and Isolate CI-4.

Cross-references

Sequence databases

EMBL
GenBank
DDBJ
K02725 Genomic RNA. Translation: AAA46375.1.
K02726 Genomic RNA. Translation: AAA46376.1.

3D structure databases

ProteinModelPortalP03388.
SMRP03388. Positions 38-230, 487-539.
ModBaseSearch...
MobiDBSearch...

Protocols and materials databases

StructuralBiologyKnowledgebaseSearch...

Family and domain databases

Gene3D3.90.310.10. 1 hit.
InterProIPR008981. FMuLV_rcpt-bd.
IPR018154. TLV/ENV_coat_polyprotein.
[Graphical view]
PANTHERPTHR10424. PTHR10424. 1 hit.
PfamPF00429. TLV_coat. 1 hit.
[Graphical view]
SUPFAMSSF49830. SSF49830. 1 hit.
ProtoNetSearch...

Entry information

Entry nameENV_MCFF3
AccessionPrimary (citable) accession number: P03388
Secondary accession number(s): Q85501
Entry history
Integrated into UniProtKB/Swiss-Prot: July 21, 1986
Last sequence update: July 21, 1986
Last modified: February 19, 2014
This is version 99 of the entry and version 1 of the sequence. [Complete history]
Entry statusReviewed (UniProtKB/Swiss-Prot)
Annotation programViral Protein Annotation Program