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P21443 (ENV_FLVC6) Reviewed, UniProtKB/Swiss-Prot

Last modified February 19, 2014. Version 83. 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
OrganismFeline leukemia virus (isolate CFE-6)
Taxonomic identifier11922 [NCBI]
Taxonomic lineageVirusesRetro-transcribing virusesRetroviridaeOrthoretrovirinaeGammaretrovirus
Virus hostFelidae (cat family) [TaxID: 9681]

Protein attributes

Sequence length668 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 extravirion 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 transmembrane protein is palmitoylated By similarity.

The R-peptide is palmitoylated By similarity.

Sequence annotation (Features)

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifier

Molecule processing

Signal peptide1 – 3434 Potential
Chain35 – 668634Envelope glycoprotein
PRO_0000239561
Chain35 – 465431Surface protein By similarity
PRO_0000040706
Chain466 – 644179Transmembrane protein By similarity
PRO_0000040707
Peptide645 – 66824R-peptide By similarity
PRO_0000239562

Regions

Topological domain35 – 605571Extracellular Potential
Transmembrane606 – 62621Helical; Potential
Topological domain627 – 66842Cytoplasmic Potential
Region467 – 48721Fusion peptide Potential
Region533 – 54917Immunosuppression By similarity
Coiled coil495 – 54450 Potential
Coiled coil554 – 59037 Potential
Motif332 – 3354CXXC
Motif550 – 5589CX6CC
Motif650 – 6534YXXL motif; contains endocytosis signal By similarity

Sites

Site465 – 4662Cleavage; by host By similarity
Site644 – 6452Cleavage; by viral protease By similarity

Amino acid modifications

Lipidation6251S-palmitoyl cysteine; by host By similarity
Glycosylation431N-linked (GlcNAc...); by host Potential
Glycosylation581N-linked (GlcNAc...); by host Potential
Glycosylation2861N-linked (GlcNAc...); by host Potential
Glycosylation3221N-linked (GlcNAc...); by host Potential
Glycosylation3271N-linked (GlcNAc...); by host Potential
Glycosylation3511N-linked (GlcNAc...); by host Potential
Glycosylation3541N-linked (GlcNAc...); by host Potential
Glycosylation3941N-linked (GlcNAc...); by host Potential
Glycosylation4101N-linked (GlcNAc...); by host Potential
Glycosylation4301N-linked (GlcNAc...); by host Potential
Disulfide bond115 ↔ 132 By similarity
Disulfide bond124 ↔ 137 By similarity
Disulfide bond332 ↔ 558Interchain (between SU and TM chains, or C-335 with C-558); alternate By similarity
Disulfide bond332 ↔ 335Alternate By similarity
Disulfide bond550 ↔ 557 By similarity

Sequences

Sequence LengthMass (Da)Tools
P21443 [UniParc].

Last modified May 1, 1991. Version 1.
Checksum: 4A6A06CF2EB8CE25

FASTA66874,298
        10         20         30         40         50         60 
MEGPTHPKPS KDKTFSWDLI ILVGVLLRLD AGMANPSPHQ VYNITWTITN LVTGIKANAT 

        70         80         90        100        110        120 
SMLGTLTDTF PTIYFDLCDI IGNTWNPSDQ EPFPGYGCDQ PMRRWQQRNT AFYVCPGHAN 

       130        140        150        160        170        180 
RKQCGGPQDG FCAVWGCETT GETYWKPTSS WDYITVKKGV TQGIYQCNGG GWCGPCYDKA 

       190        200        210        220        230        240 
VHSSTTGASE GGRCNPLILQ FTQKGRQTSW DGPKSWGLRL YRSGYDPIAL FSVSRQVMTI 

       250        260        270        280        290        300 
TPPQAMGPNP VLPDQKPPSR QSQIESRVIP HHPQGNGGTP GITLVNASIA PLSTPVTPAS 

       310        320        330        340        350        360 
PKRIGTGNRL INLVQGTYLT LNVTNPNKTK DCWLCLVSRP PYYEGIAVLG NYSNQTNPPP 

       370        380        390        400        410        420 
SCLSVPQHKL TISEVSGQGL CIATVPKTHQ ALCNKTQKGH RGTHYLVAPN GTYWACNTGL 

       430        440        450        460        470        480 
TPCISMAVLN WTSDFCVLTE LWPRITYHEP EYIYSHFENK PRFKRDPISL TVALMLGGIT 

       490        500        510        520        530        540 
VGGMARNRNR DCGLLETAQF RQLQMAMHTD IQALEESISA LEKSLTSLSE VVLQNRRGLD 

       550        560        570        580        590        600 
ILFLQEGGLC TALKEECCFY ADHTGLVRDN MAKLRERLKQ RQQLFDSQQD GLEGWFNKSP 

       610        620        630        640        650        660 
WFTTLISSIM GPLMILLLIL LFGPCILNRL VQFVKDRISV VQTLVLTQQY QRLGQWRLRP 


TVSPQLNV 

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References

[1]"Nucleotide sequence and distinctive characteristics of the env gene of endogenous feline leukemia provirus."
Kumar D.V., Berry B.T., Roy-Burman P.
J. Virol. 63:2379-2384(1989) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA].

Cross-references

Sequence databases

EMBL
GenBank
DDBJ
M25425 Genomic DNA. Translation: AAA30809.1.

3D structure databases

ProteinModelPortalP21443.
SMRP21443. Positions 38-242, 510-562.
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_FLVC6
AccessionPrimary (citable) accession number: P21443
Entry history
Integrated into UniProtKB/Swiss-Prot: May 1, 1991
Last sequence update: May 1, 1991
Last modified: February 19, 2014
This is version 83 of the entry and version 1 of the sequence. [Complete history]
Entry statusReviewed (UniProtKB/Swiss-Prot)
Annotation programViral Protein Annotation Program