UniProt functional annotation for P03397



	UniProt functional annotation for P03397

UniProt code: P03397.

Organism: Avian leukosis virus RSA (RSV-SRA) (Rous sarcoma virus (strain Schmidt-Ruppin A)).

Taxonomy: Viruses; Riboviria; Pararnavirae; Artverviricota; Revtraviricetes; Ortervirales; Retroviridae; Orthoretrovirinae; Alpharetrovirus.

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). {ECO:0000250}.

Function: 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). {ECO:0000250}.

Subunit: The mature envelope protein (Env) consists of a trimer of SU- TM heterodimers attached by a labile interchain disulfide bond. {ECO:0000250}.

Subcellular location: [Transmembrane protein]: Virion membrane {ECO:0000250}; Single-pass type I membrane protein {ECO:0000250}. Host cell membrane {ECO:0000250}; Single-pass type I membrane protein {ECO:0000250}.

Subcellular location: [Surface protein]: Virion membrane; Peripheral membrane protein. Host cell membrane {ECO:0000250}; Peripheral membrane protein {ECO:0000250}. 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). {ECO:0000250}.

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). {ECO:0000250}.

Ptm: Specific enzymatic cleavages in vivo yield mature proteins. Envelope glycoproteins are synthesized as an 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 (By similarity). {ECO:0000250}.

Ptm: The transmembrane protein is palmitoylated. Palmitoylation is necessary for glycoprotein function and infectivity (By similarity). {ECO:0000250}.

Annotations taken from UniProtKB at the EBI.


Organism:		Avian leukosis virus RSA (RSV-SRA) (Rous sarcoma virus (strain Schmidt-Ruppin A)).
Taxonomy:		Viruses; Riboviria; Pararnavirae; Artverviricota; Revtraviricetes; Ortervirales; Retroviridae; Orthoretrovirinae; Alpharetrovirus.



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). {ECO:0000250}.



Function:		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). {ECO:0000250}.


Subunit:		The mature envelope protein (Env) consists of a trimer of SU- TM heterodimers attached by a labile interchain disulfide bond. {ECO:0000250}.
Subcellular location:		[Transmembrane protein]: Virion membrane {ECO:0000250}; Single-pass type I membrane protein {ECO:0000250}. Host cell membrane {ECO:0000250}; Single-pass type I membrane protein {ECO:0000250}.
Subcellular location:		[Surface protein]: Virion membrane; Peripheral membrane protein. Host cell membrane {ECO:0000250}; Peripheral membrane protein {ECO:0000250}. 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). {ECO:0000250}.
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). {ECO:0000250}.
Ptm:		Specific enzymatic cleavages in vivo yield mature proteins. Envelope glycoproteins are synthesized as an 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 (By similarity). {ECO:0000250}.
Ptm:		The transmembrane protein is palmitoylated. Palmitoylation is necessary for glycoprotein function and infectivity (By similarity). {ECO:0000250}.