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Q2F7I8 (ENV_XMRV4) Reviewed, UniProtKB/Swiss-Prot

Last modified April 3, 2013. Version 32. 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
  2. Transmembrane protein
    Short name=TM
  3. R-peptide
Gene names
Name:env
OrganismXenotropic MuLV-related virus (isolate VP42) (XMRV) [Complete proteome]
Taxonomic identifier356664 [NCBI]
Taxonomic lineageViruses › Retro-transcribing viruses › Retroviridae › Orthoretrovirinae › Gammaretrovirus › unclassified Gammaretrovirus ›
Virus hostHomo sapiens (Human) [TaxID: 9606]

Protein attributes

Sequence length645 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 activates a thiol in a CXXC motif of the C-terminal domain, where the other Cys residue participates in the formation of the intersubunit disulfide. The activated thiol will attack the disulfide and cause its isomerization into a disulfide isomer within the motif. This leads to SU displacement and TM refolding, 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. The activated Env consists of SU monomers and TM trimers 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. 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 By similarity.

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 transmembrane protein is palmitoylated By similarity.

The R-peptide is palmitoylated.

Sequence annotation (Features)

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifier

Molecule processing

Signal peptide1 – 3333 Potential
Chain34 – 640607Envelope glycoprotein By similarity
PRO_0000390827
Chain34 – 444411Surface protein By similarity
PRO_0000390828
Chain445 – 645201Transmembrane protein By similarity
PRO_0000390829
Peptide625 – 64521R-peptide By similarity
PRO_0000390830

Regions

Topological domain34 – 585552Extracellular Potential
Transmembrane586 – 60621Helical; Potential
Topological domain607 – 64034Cytoplasmic Potential
Region32 – 237206Receptor-binding domain (RBD) Potential
Region447 – 46721Fusion peptide By similarity
Region513 – 52917Immunosuppression By similarity
Coiled coil490 – 51021 Potential
Motif311 – 3144CXXC By similarity
Motif530 – 5389CX6CC By similarity
Motif630 – 6334YXXL motif; contains endocytosis signal By similarity
Compositional bias234 – 28350Pro-rich

Sites

Site444 – 4452Cleavage; by host By similarity
Site624 – 6252Cleavage; by viral protease p14 By similarity

Amino acid modifications

Lipidation6051S-palmitoyl cysteine; by host By similarity
Glycosylation431N-linked (GlcNAc...); by host Potential
Glycosylation581N-linked (GlcNAc...); by host Potential
Glycosylation3011N-linked (GlcNAc...); by host Potential
Glycosylation3331N-linked (GlcNAc...); by host Potential
Glycosylation3401N-linked (GlcNAc...); by host Potential
Glycosylation3731N-linked (GlcNAc...); by host Potential
Glycosylation4091N-linked (GlcNAc...); by host Potential
Disulfide bond113 ↔ 130 By similarity
Disulfide bond122 ↔ 135 By similarity
Disulfide bond311 ↔ 538Interchain (between SU and TM chains, or C-314 with C-538); alternate By similarity
Disulfide bond311 ↔ 314Alternate By similarity
Disulfide bond341 ↔ 395 By similarity
Disulfide bond360 ↔ 372 By similarity
Disulfide bond402 ↔ 415 By similarity
Disulfide bond530 ↔ 537 By similarity

Sequences

Sequence LengthMass (Da)Tools
Q2F7I8 [UniParc].

Last modified March 21, 2006. Version 1.
Checksum: 7F4B9F26F5857E53

FASTA64569,887
        10         20         30         40         50         60 
MESPAFSKPL KDKINPWGPL IIMGILVRAG ASVQRDSPHQ VFNVTWKITN LMTGQTANAT 

        70         80         90        100        110        120 
SLLGTMTDTF PKLYFDLCDL VGDNWDDPEP DIGDGCRSPG GRKRTRLYDF YVCPGHTVLT 

       130        140        150        160        170        180 
GCGGPREGYC GKWGCETTGQ AYWKPSSSWD LISLKRGNTP KGQGPCFDSS VGSGSIQGAT 

       190        200        210        220        230        240 
PGGRCNPLVL EFTDAGKRAS WDAPKTWGLR LYRSTGADPV TLFSLTRQVL NVGPRVPIGP 

       250        260        270        280        290        300 
NPVITEQLPP SQPVQIMLPR PPRPPPSGAA SMVPGAPPPS QQPGTGDRLL NLVEGAYQAL 

       310        320        330        340        350        360 
NLTSPDKTQE CWLCLVSGPP YYEGVAVLGT YSNHTSAPAN CSVTSQHKLT LSEVTGQGLC 

       370        380        390        400        410        420 
IGAVPKTHQA LCNTTQKTSD GSYYLASPAG TIWACSTGLT PCLSTTVLNL TTDYCVLVEL 

       430        440        450        460        470        480 
WPKVTYHSPN YVYGQFEKKT KYKREPVSLT LALLLGGLTM GGIAAGVGTG TTALVATKQF 

       490        500        510        520        530        540 
EQLQAAIHTD LGALEKSVSA LEKSLTSLSE VVLQNRRGLD LLFLKEGGLC AALKEECCFY 

       550        560        570        580        590        600 
ADHTGVVRDS MAKLRERLNQ RQKLFESGQG WFEGLFNRSP WFTTLISTIM GPLIVLLLIL 

       610        620        630        640 
LFGPCILNRL VQFVKDRISV VQALVLTQQY HQLKSIDPEE VESRE

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References

[1]"Identification of a novel Gammaretrovirus in prostate tumors of patients homozygous for R462Q RNASEL variant."
Urisman A., Molinaro R.J., Fischer N., Plummer S.J., Casey G., Klein E.A., Malathi K., Magi-Galluzzi C., Tubbs R.R., Ganem D., Silverman R.H., DeRisi J.L.
PLoS Pathog. 2:E25-E25(2006) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC RNA].

Cross-references

Sequence databases

EMBL
GenBank
DDBJ		DQ241302 Genomic RNA. Translation: ABB83229.1.

3D structure databases

ProteinModelPortalQ2F7I8.
SMRQ2F7I8. Positions 38-234, 490-542.
ModBaseSearch...

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. FMuLVrecept-bind. 1 hit.
ProtoNetSearch...

Entry information

Entry nameENV_XMRV4
AccessionPrimary (citable) accession number: Q2F7I8
Entry history
Integrated into UniProtKB/Swiss-Prot: January 19, 2010
Last sequence update: March 21, 2006
Last modified: April 3, 2013
This is version 32 of the entry and version 1 of the sequence. [Complete history]
Entry statusReviewed (UniProtKB/Swiss-Prot)
Annotation programViral Protein Annotation Program
to top of pageNames·Attributes·General annotation·Ontologies·Sequence annotation·Sequences·References·Cross-refs·Entry info