P06752 (ENV_FLVSA) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended 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

Organism

Feline leukemia virus (strain C/Sarma)

Taxonomic identifier

103919 [NCBI]

Taxonomic lineage

Viruses › Retro-transcribing viruses › Retroviridae › Orthoretrovirinae › Gammaretrovirus › Mammalian virus group › Replication competent viruses › Feline leukemia virus

Virus host

Felis catus (Cat) (Felis silvestris catus) [TaxID: 9685]

Protein attributes

Sequence length	639 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is further processed into a mature form.
Protein existence	Inferred 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.
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.

Ontologies

Keywords
Biological process	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
Cellular component	Host cell membrane Host membrane Membrane Viral envelope protein Virion
Domain	Coiled coil Signal Transmembrane Transmembrane helix
PTM	Cleavage on pair of basic residues Disulfide bond Glycoprotein Lipoprotein Palmitate
Gene Ontology (GO)
Biological_process	viral attachment to host cell Inferred from electronic annotation. Source: UniProtKB-KW viral entry into host cell via membrane fusion with the plasma membrane Inferred from electronic annotation. Source: UniProtKB-KW viral infectious cycle Inferred from electronic annotation. Source: InterPro
Cellular_component	host cell plasma membrane Inferred from electronic annotation. Source: UniProtKB-SubCell integral to membrane Inferred from electronic annotation. Source: UniProtKB-KW viral capsid Inferred from electronic annotation. Source: InterPro viral envelope Inferred from electronic annotation. Source: UniProtKB-KW virion membrane Inferred from electronic annotation. Source: UniProtKB-SubCell
Molecular_function	structural molecule activity Inferred from electronic annotation. Source: InterPro
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Signal peptide	1 – 34	34	Potential
	Chain	35 – 639	605	Envelope glycoprotein		PRO_0000239568
	Chain	35 – 442	408	Surface protein By similarity		PRO_0000040716
	Chain	443 – 622	180	Transmembrane protein By similarity		PRO_0000040717
	Peptide	623 – 639	17	R-peptide By similarity		PRO_0000239569
Regions
	Topological domain	35 – 583	549	Extracellular Potential
	Transmembrane	584 – 604	21	Helical; Potential
	Topological domain	605 – 639	35	Cytoplasmic Potential
	Region	445 – 465	21	Fusion peptide Potential
	Region	511 – 527	17	Immunosuppression By similarity
	Coiled coil	473 – 522	50	Potential
	Coiled coil	532 – 568	37	Potential
	Motif	309 – 312	4	CXXC
	Motif	528 – 536	9	CX6CC
Sites
	Site	442 – 443	2	Cleavage; by host By similarity
	Site	622 – 623	2	Cleavage; by viral protease By similarity
Amino acid modifications
	Lipidation	603	1	S-palmitoyl cysteine; by host By similarity
	Glycosylation	35	1	N-linked (GlcNAc...); by host Potential
	Glycosylation	43	1	N-linked (GlcNAc...); by host Potential
	Glycosylation	58	1	N-linked (GlcNAc...); by host Potential
	Glycosylation	299	1	N-linked (GlcNAc...); by host Potential
	Glycosylation	304	1	N-linked (GlcNAc...); by host Potential
	Glycosylation	328	1	N-linked (GlcNAc...); by host Potential
	Glycosylation	331	1	N-linked (GlcNAc...); by host Potential
	Glycosylation	387	1	N-linked (GlcNAc...); by host Potential
	Glycosylation	407	1	N-linked (GlcNAc...); by host Potential
	Disulfide bond	122 ↔ 144		By similarity
	Disulfide bond	136 ↔ 149		By similarity
	Disulfide bond	309 ↔ 536		Interchain (between SU and TM chains, or C-312 with C-536); alternate By similarity
	Disulfide bond	309 ↔ 312		Alternate By similarity
	Disulfide bond	528 ↔ 535		By similarity

Sequences

	Sequence		Length	Mass (Da)
	P06752 [UniParc]. Last modified January 1, 1988. Version 1. Checksum: A309B64AC8EC74E4	FASTA	639	71,162
	10 20 30 40 50 60 MESPTHPKPS KDKTFPWNLV FLVGILFQID MGMANPSPHQ VYNVTWVITN VQTNSRANAT 70 80 90 100 110 120 SMLGTLTDAY PTLYVDLCDL VGDTWEPIAP DPRSWARYSS STHGCKTTDR KKQQQTYPFY 130 140 150 160 170 180 VCPGHAPSMG PKGTYCGGAQ DGFCAAWGCE TTGEAWWKPT SSWDYITVKR GSNQDNSCKG 190 200 210 220 230 240 KCNPLVLQFT QKGRQASWDR PKMWGLRLYR SGYDPIALFS VSRQVMTITP PQAMGPNLVL 250 260 270 280 290 300 PDQKPPSRQS QTKSKVTTQR PQITSSTPRS VASATMGPKR IGTGDRLINL VQGTYLALNA 310 320 330 340 350 360 TDPNKTKDCW LCLVSRPPYY EGIAVLGNYS NQTNPPPSCL STPQHKLTIS EVSGQGLCIG 370 380 390 400 410 420 TVPKTHQALC KKTQKGHKGT HYLAAPNGTY WACNTGLTPC ISMAVLNWTS DFCVLIELWP 430 440 450 460 470 480 RVTYHQPEYI YTHFDKAVRF RREPISLTVA LMLGGLTVGG IAAGVGTGTK ALLETAQFRQ 490 500 510 520 530 540 LQIAMHTDIQ ALEESISALE KSLTSLSEVV LQNRRGLDIL FLQEGGLCAA LKEECCFYAD 550 560 570 580 590 600 HTGLVRDNMA KLRERLKQRQ QLFDSQQGWF EGWFNKSPWF TTLISSIMGP LLILLLILLL 610 620 630 GPCILNRLVQ FVKDRISVVQ ALILTQQYQQ IQQYDSDRP

References

[1]	"Molecular analysis and pathogenesis of the feline aplastic anemia retrovirus, feline leukemia virus C-Sarma." Riedel N., Hoover E.A., Gasper P.W., Nicolson M.O., Mullins J.I. J. Virol. 60:242-250(1986) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA].

Cross-references

Sequence databases
EMBL GenBank DDBJ	M14331 Genomic DNA. Translation: AAA43049.1.
PIR	VCMVSA. A29013. A46165.
3D structure databases
ProteinModelPortal	P06752.
SMR	P06752. Positions 38-230, 488-540.
ModBase	Search...
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Family and domain databases
Gene3D	3.90.310.10. 1 hit.
InterPro	IPR008981. FMuLV_rcpt-bd. IPR018154. TLV/ENV_coat_polyprotein. [Graphical view]
PANTHER	PTHR10424. PTHR10424. 1 hit.
Pfam	PF00429. TLV_coat. 1 hit. [Graphical view]
SUPFAM	SSF49830. FMuLVrecept-bind. 1 hit.
ProtoNet	Search...

Entry information

Entry name

ENV_FLVSA

Accession

Primary (citable) accession number: P06752

Entry history

Integrated into UniProtKB/Swiss-Prot:	January 1, 1988
Last sequence update:	January 1, 1988
Last modified:	April 3, 2013
This is version 83 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Viral Protein Annotation Program