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Protein

Envelope glycoprotein

Gene

env

Organism
Koala retrovirus (KoRV)
Status
Reviewed-Annotation score: Annotation score: 5 out of 5-Protein inferred from homologyi

Functioni

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).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).By similarity

GO - Molecular functioni

GO - Biological processi

Complete GO annotation...

Keywords - Biological processi

Fusion of virus membrane with host cell membrane, Fusion of virus membrane with host membrane, Host-virus interaction, Viral attachment to host cell, Viral penetration into host cytoplasm, Virus entry into host cell

Names & Taxonomyi

Protein namesi
Recommended name:
Envelope glycoprotein
Alternative name(s):
Env polyprotein
Cleaved into the following 3 chains:
Surface protein
Short name:
SU
Alternative name(s):
Glycoprotein 70
Short name:
gp70
Transmembrane protein
Short name:
TM
Alternative name(s):
Envelope protein p15E
Alternative name(s):
p2E
Gene namesi
Name:env
OrganismiKoala retrovirus (KoRV)
Taxonomic identifieri394239 [NCBI]
Taxonomic lineageiVirusesRetro-transcribing virusesRetroviridaeOrthoretrovirinaeGammaretrovirusunclassified Gammaretrovirus
Virus hostiPhascolarctos cinereus (Koala) [TaxID: 38626]
Proteomesi
  • UP000007765 Componenti: Genome

Subcellular locationi

Surface protein :
  • Virion membrane; Peripheral membrane protein
  • Host cell membrane By similarity; 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).By similarity
Peptide R-peptide :

Topology

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Topological domaini36 – 606ExtracellularSequence analysisAdd BLAST571
Transmembranei607 – 627HelicalSequence analysisAdd BLAST21
Topological domaini628 – 659CytoplasmicSequence analysisAdd BLAST32

GO - Cellular componenti

Complete GO annotation...

Keywords - Cellular componenti

Host cell membrane, Host membrane, Membrane, Viral envelope protein, Virion

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Signal peptidei1 – 35Sequence analysisAdd BLAST35
ChainiPRO_000024942336 – 659Envelope glycoproteinAdd BLAST624
ChainiPRO_000024942436 – 463Surface proteinBy similarityAdd BLAST428
ChainiPRO_0000249425464 – 659Transmembrane proteinBy similarityAdd BLAST196
PeptideiPRO_0000249426645 – 659R-peptideBy similarityAdd BLAST15

Amino acid modifications

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Disulfide bondi141 ↔ 162By similarity
Disulfide bondi154 ↔ 167By similarity
Glycosylationi318N-linked (GlcNAc...); by hostSequence analysis1
Disulfide bondi328 ↔ 558Interchain (between SU and TM chains, or C-357 with C-584); in linked formBy similarity
Disulfide bondi328 ↔ 331By similarity
Glycosylationi389N-linked (GlcNAc...); by hostSequence analysis1
Glycosylationi395N-linked (GlcNAc...); by hostSequence analysis1
Glycosylationi407N-linked (GlcNAc...); by hostSequence analysis1
Glycosylationi427N-linked (GlcNAc...); by hostSequence analysis1
Disulfide bondi550 ↔ 557By similarity
Lipidationi625S-palmitoyl cysteine; by hostBy similarity1

Post-translational modificationi

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).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).By similarity
The transmembrane protein is palmitoylated.By similarity
The R-peptide is palmitoylated.By similarity

Sites

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Sitei463 – 464Cleavage; by hostBy similarity2
Sitei643 – 644Cleavage; by viral proteaseBy similarity2

Keywords - PTMi

Cleavage on pair of basic residues, Disulfide bond, Glycoprotein, Lipoprotein, Palmitate

Interactioni

Subunit structurei

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

Structurei

3D structure databases

ProteinModelPortaliQ9TTC0.
ModBaseiSearch...
MobiDBiSearch...

Family & Domainsi

Region

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Regioni466 – 486Fusion peptideBy similarityAdd BLAST21
Regioni533 – 549ImmunosuppressionBy similarityAdd BLAST17

Coiled coil

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Coiled coili506 – 532Sequence analysisAdd BLAST27
Coiled coili567 – 587Sequence analysisAdd BLAST21

Motif

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Motifi328 – 331CXXCBy similarity4
Motifi550 – 558CX6CCBy similarity9
Motifi650 – 653YXXL motif; contains endocytosis signalBy similarity4

Domaini

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).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

Keywords - Domaini

Coiled coil, Signal, Transmembrane, Transmembrane helix

Family and domain databases

Gene3Di3.90.310.10. 1 hit.
InterProiIPR008981. FMuLV_rcpt-bd.
IPR018154. TLV/ENV_coat_polyprotein.
[Graphical view]
PANTHERiPTHR10424. PTHR10424. 2 hits.
PfamiPF00429. TLV_coat. 1 hit.
[Graphical view]
SUPFAMiSSF49830. SSF49830. 1 hit.

Sequencei

Sequence statusi: Complete.

Sequence processingi: The displayed sequence is further processed into a mature form.

Q9TTC0-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
MLLISNPRHL GHPMSPGNWK RLIILLSCVF GGAEMNQQHN NPHQPMTLTW
60 70 80 90 100
QVLSQTGSVV WEKKAVEPPW TWWPSLEPDV CALVAGLESW DIPELTASAS
110 120 130 140 150
QQARPPDSNY EHAYNQITWG TLGCSYPRAR TRIARSQFYV CPRDGRSLSE
160 170 180 190 200
ARRCGGLESL YCKEWGCETA GTAYWQPRSS WDLITVGQGH PTGTCERTGW
210 220 230 240 250
CNPLKIEFTE PGKRFRNWLQ GRTWGLRFYV TGHPGVQLTI RLVITSPPPV
260 270 280 290 300
VVGPDPVLAE QGPPRKIPFL PRVPVPTLSP PASPIPTVQA SPPAPSTPSP
310 320 330 340 350
TTGDRLFGLV QGAFLALNAT NPEATESCWL CLALGPPYYE GIATPGQVTY
360 370 380 390 400
ASTDSQCRWG GKGKLTLTEV SGLGLCIGKV PPTHQHLCNL TIPLNASHTH
410 420 430 440 450
KYLLPSNRSW WACNSGLTPC LSTSVFNQSN DFCIQIQLVP RIYYHPDGTL
460 470 480 490 500
LQAYESPHSR NKREPVSLTL AVLLGLGVAA GIGTGSTALI KGPIDLQQGL
510 520 530 540 550
TSLQIAMDTD LRALQDSISK LEDSLTSLSE VVLQNRRGLD LLFLKEGGLC
560 570 580 590 600
AALKEECCFY VDHSGAVRDS MRRLKERLDK RQLEHQKNLS WYEGWFNRSP
610 620 630 640 650
WLTTLLSALA GPLLLLLLLL TLGPCVINKL VQFINDRVSA VRILVLRHKY

QTLDNEDNL
Length:659
Mass (Da):72,860
Last modified:May 1, 2000 - v1
Checksum:i68B2220DAA6A2ABA
GO

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
AF151794 Genomic DNA. Translation: AAF15099.1.

Cross-referencesi

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
AF151794 Genomic DNA. Translation: AAF15099.1.

3D structure databases

ProteinModelPortaliQ9TTC0.
ModBaseiSearch...
MobiDBiSearch...

Protocols and materials databases

Structural Biology KnowledgebaseSearch...

Family and domain databases

Gene3Di3.90.310.10. 1 hit.
InterProiIPR008981. FMuLV_rcpt-bd.
IPR018154. TLV/ENV_coat_polyprotein.
[Graphical view]
PANTHERiPTHR10424. PTHR10424. 2 hits.
PfamiPF00429. TLV_coat. 1 hit.
[Graphical view]
SUPFAMiSSF49830. SSF49830. 1 hit.
ProtoNetiSearch...

Entry informationi

Entry nameiENV_KORV
AccessioniPrimary (citable) accession number: Q9TTC0
Entry historyi
Integrated into UniProtKB/Swiss-Prot: September 5, 2006
Last sequence update: May 1, 2000
Last modified: October 5, 2016
This is version 78 of the entry and version 1 of the sequence. [Complete history]
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programViral Protein Annotation Program

Miscellaneousi

Miscellaneous

Koala retrovirus is both a circulating virus and an endogenous retrovirus of koala, except in some isolated populations in south Australia.

Keywords - Technical termi

Complete proteome

Similar proteinsi

Links to similar proteins from the UniProt Reference Clusters (UniRef) at 100%, 90% and 50% sequence identity:
100%UniRef100 combines identical sequences and sub-fragments with 11 or more residues from any organism into one UniRef entry.
90%UniRef90 is built by clustering UniRef100 sequences that have at least 90% sequence identity to, and 80% overlap with, the longest sequence (a.k.a seed sequence).
50%UniRef50 is built by clustering UniRef90 seed sequences that have at least 50% sequence identity to, and 80% overlap with, the longest sequence in the cluster.