Q02381 · POLG_HAVGA
- ProteinGenome polyprotein
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids808 (go to sequence)
- Protein existenceInferred from homology
- Annotation score4/5
Function
function
Capsid protein VP1
Capsid proteins VP1, VP2, and VP3 form a closed capsid enclosing the viral positive strand RNA genome. All these proteins contain a beta-sheet structure called beta-barrel jelly roll. Together they form an icosahedral capsid (T=3) composed of 60 copies of each VP1, VP2, and VP3, with a diameter of approximately 300 Angstroms. VP1 is situated at the 12 fivefold axes, whereas VP2 and VP3 are located at the quasi-sixfold axes. The naked capsid interacts with the host receptor HAVCR1 to provide virion attachment to and probably entry into the target cell.
Capsid protein VP2
Capsid proteins VP1, VP2, and VP3 form a closed capsid enclosing the viral positive strand RNA genome. All these proteins contain a beta-sheet structure called beta-barrel jelly roll. Together they form an icosahedral capsid (T=3) composed of 60 copies of each VP1, VP2, and VP3, with a diameter of approximately 300 Angstroms. VP1 is situated at the 12 fivefold axes, whereas VP2 and VP3 are located at the quasi-sixfold axes. The naked capsid interacts with the host receptor HAVCR1 to provide virion attachment to and probably entry into the target cell.
Capsid protein VP3
Capsid proteins VP1, VP2, and VP3 form a closed capsid enclosing the viral positive strand RNA genome. All these proteins contain a beta-sheet structure called beta-barrel jelly roll. Together they form an icosahedral capsid (T=3) composed of 60 copies of each VP1, VP2, and VP3, with a diameter of approximately 300 Angstroms. VP1 is situated at the 12 fivefold axes, whereas VP2 and VP3 are located at the quasi-sixfold axes. The naked capsid interacts with the host receptor HAVCR1 to provide virion attachment to and probably entry into the target cell.
Capsid protein VP0
VP0 precursor is a component of the immature procapsids.
Capsid protein VP4
Plays a role in the assembly of the 12 pentamers into an icosahedral structure. Has not been detected in mature virions, supposedly owing to its small size.
Protein VP1-2A
Precursor component of immature procapsids that corresponds to an extended form of the structural protein VP1. After maturation, possibly by the host Cathepsin L, the assembly signal 2A is cleaved to give rise to the mature VP1 protein.
Miscellaneous
Genome polyprotein
The need for an intact eIF4G factor for the initiation of translation of HAV results in an inability to shut off host protein synthesis by a mechanism similar to that of other picornaviruses.
Genome polyprotein
During infection, enveloped virions (eHAV) are released from cells. These eHAV are cloaked in host-derived membranes and resemble exosomes. The membrane of eHAV is devoid of viral proteins and thus prevents their neutralization by antibodies. eHAV budding is dependent on ESCRT-associated proteins VPS4B and PDCD6IP/ALIX. eHAV are produced and released in the serum and plasma, but not in bile and feces which only contain the naked, nonenveloped virions. It is likely that eHAV also use HAVCR1 as a functional receptor to infect cells, an evolutionary trait that may enhance HAV infectivity.
Features
Showing features for site.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Site | 2-3 | Cleavage | ||||
Sequence: AD | ||||||
Site | 224-225 | Cleavage; by protease 3C | ||||
Sequence: QM | ||||||
Site | 470-471 | Cleavage; by protease 3C | ||||
Sequence: QV | ||||||
Site | 744-745 | Cleavage; partial; by host | ||||
Sequence: TV | ||||||
Site | 748 | Important for VP1 folding and capsid assembly | ||||
Sequence: R |
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | host cell membrane | |
Cellular Component | host multivesicular body | |
Cellular Component | T=pseudo3 icosahedral viral capsid | |
Molecular Function | channel activity | |
Molecular Function | structural molecule activity | |
Biological Process | monoatomic ion transmembrane transport | |
Biological Process | symbiont entry into host cell | |
Biological Process | virion attachment to host cell |
Keywords
- Molecular function
- Biological process
Names & Taxonomy
Protein names
- Recommended nameGenome polyprotein
- Cleaved into 7 chains
Organism names
- Taxonomic lineageViruses > Riboviria > Orthornavirae > Pisuviricota > Pisoniviricetes > Picornavirales > Picornaviridae > Heptrevirinae > Hepatovirus > Hepatovirus A
- Virus hosts
Accessions
- Primary accessionQ02381
Subcellular Location
UniProt Annotation
GO Annotation
Capsid protein VP2
Note: The egress of newly formed virions occurs through an exosome-like mechanism involving endosomal budding of viral capsids into multivesicular bodies.
Capsid protein VP3
Note: The egress of newly formed virions occurs through an exosome-like mechanism involving endosomal budding of viral capsids into multivesicular bodies.
Capsid protein VP1
Note: The egress of newly formed virions occurs through an exosome-like mechanism involving endosomal budding of viral capsids into multivesicular bodies.
Capsid protein VP4
Note: Present in the full mature virion. The egress of newly formed virions occurs through an exosome-like mechanism involving endosomal budding of viral capsids into multivesicular bodies.
Keywords
- Cellular component
PTM/Processing
Features
Showing features for chain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Chain | PRO_0000039941 | 1-2 | Capsid protein VP4 | |||
Sequence: LA | ||||||
Chain | PRO_0000311005 | 1-224 | Capsid protein VP0 | |||
Sequence: LADVEEEQMIQSVDRTAVTGASYFTSVDQSSVHTAEVGSHQPEPLKTSVDKPGSKRTQGEKFFLIHSADWLTTHALFHEVAKLDVVKLLYNEQFAVQGLLRYHTYARFGIEIQVQINPTPFQQGGLICAMVPGDQSYGSIASLTVYPHGLLNCNINNVVRIKVPFIYTRGAYHFKDPQYPVWELTIRVWSELNIGTGTSAYTSLNVLARFTDLELHGLTPLSTQ | ||||||
Chain | PRO_0000311004 | 1-808 | Genome polyprotein | |||
Sequence: LADVEEEQMIQSVDRTAVTGASYFTSVDQSSVHTAEVGSHQPEPLKTSVDKPGSKRTQGEKFFLIHSADWLTTHALFHEVAKLDVVKLLYNEQFAVQGLLRYHTYARFGIEIQVQINPTPFQQGGLICAMVPGDQSYGSIASLTVYPHGLLNCNINNVVRIKVPFIYTRGAYHFKDPQYPVWELTIRVWSELNIGTGTSAYTSLNVLARFTDLELHGLTPLSTQMMRNEFRVSTTENVVNLSNYEDARAKMSFALDQEDWKSDASQGGGIKITHFTTWTSIPTLAAQFPFNASDSVGQQIKVIPVDPYFFQMTNTNPEQKCITALASICQMFCFWRGDLVFDFQVFPTKYHSGRLLFCFVPGNELIDVSHITLKQATTAPCAVMDITGVQSTLRFRVPWISDTPYRVNRYTKSSHQKGEYTAIGKLIVYCYNRLTSPSNVASHVRVNVYLSAINLECFAPLYHAMDVTTQVGDDSGGFSTTVSTKQNVPDPQVGITTVKDLKGRANQGKMDISGVQAPVGAITTIEDPVLAKKVPETFPELKPGESRHTSDHMSIYKFMGRSHFLCTFTFNSNNKEYTFPITLSSTSNPPHGLPATLRWFFNLFQLYRGPLDLTIIITGATDVDGMAWFTPVGLAVDTPWVEKESALSIDYKTALGAVRFNTRRTGNDQIRLPWYSYLYAVSGALDGLGDKTDSTFGLVSIQIANYNHSDEYLSFSCYLSVTEQSEFYFPRAPLNTNAMMSSETVMDRIALGDLESSVDDPRTEEDRKFESHIEKRKPYKELRLEVGKQRLKYAQEELSNEVLPPPRK | ||||||
Chain | PRO_0000039942 | 3-224 | Capsid protein VP2 | |||
Sequence: DVEEEQMIQSVDRTAVTGASYFTSVDQSSVHTAEVGSHQPEPLKTSVDKPGSKRTQGEKFFLIHSADWLTTHALFHEVAKLDVVKLLYNEQFAVQGLLRYHTYARFGIEIQVQINPTPFQQGGLICAMVPGDQSYGSIASLTVYPHGLLNCNINNVVRIKVPFIYTRGAYHFKDPQYPVWELTIRVWSELNIGTGTSAYTSLNVLARFTDLELHGLTPLSTQ | ||||||
Chain | PRO_0000039943 | 225-470 | Capsid protein VP3 | |||
Sequence: MMRNEFRVSTTENVVNLSNYEDARAKMSFALDQEDWKSDASQGGGIKITHFTTWTSIPTLAAQFPFNASDSVGQQIKVIPVDPYFFQMTNTNPEQKCITALASICQMFCFWRGDLVFDFQVFPTKYHSGRLLFCFVPGNELIDVSHITLKQATTAPCAVMDITGVQSTLRFRVPWISDTPYRVNRYTKSSHQKGEYTAIGKLIVYCYNRLTSPSNVASHVRVNVYLSAINLECFAPLYHAMDVTTQ | ||||||
Chain | PRO_0000039944 | 471-744 | Capsid protein VP1 | |||
Sequence: VGDDSGGFSTTVSTKQNVPDPQVGITTVKDLKGRANQGKMDISGVQAPVGAITTIEDPVLAKKVPETFPELKPGESRHTSDHMSIYKFMGRSHFLCTFTFNSNNKEYTFPITLSSTSNPPHGLPATLRWFFNLFQLYRGPLDLTIIITGATDVDGMAWFTPVGLAVDTPWVEKESALSIDYKTALGAVRFNTRRTGNDQIRLPWYSYLYAVSGALDGLGDKTDSTFGLVSIQIANYNHSDEYLSFSCYLSVTEQSEFYFPRAPLNTNAMMSSET | ||||||
Chain | PRO_0000311006 | 471-808 | Protein VP1-2A | |||
Sequence: VGDDSGGFSTTVSTKQNVPDPQVGITTVKDLKGRANQGKMDISGVQAPVGAITTIEDPVLAKKVPETFPELKPGESRHTSDHMSIYKFMGRSHFLCTFTFNSNNKEYTFPITLSSTSNPPHGLPATLRWFFNLFQLYRGPLDLTIIITGATDVDGMAWFTPVGLAVDTPWVEKESALSIDYKTALGAVRFNTRRTGNDQIRLPWYSYLYAVSGALDGLGDKTDSTFGLVSIQIANYNHSDEYLSFSCYLSVTEQSEFYFPRAPLNTNAMMSSETVMDRIALGDLESSVDDPRTEEDRKFESHIEKRKPYKELRLEVGKQRLKYAQEELSNEVLPPPRK | ||||||
Chain | PRO_0000039945 | 745-808 | Assembly signal 2A | |||
Sequence: VMDRIALGDLESSVDDPRTEEDRKFESHIEKRKPYKELRLEVGKQRLKYAQEELSNEVLPPPRK |
Post-translational modification
Genome polyprotein
Specific enzymatic cleavages by viral protease in vivo yield a variety of precursors and mature proteins. Polyprotein processing intermediates are produced, such as P1-2A which is a functional precursor of the structural proteins, VP0 which is a VP4-VP2 precursor, VP1-2A precursor, 3ABC precursor which is a stable and catalytically active precursor of 3A, 3B and 3C proteins, 3AB and 3CD precursors. The assembly signal 2A is removed from VP1-2A by a host protease, possibly host Cathepsin L. This cleavage occurs over a region of 3 amino-acids probably generating VP1 proteins with heterogeneous C-termini.
Capsid protein VP0
During virion maturation, immature virions are rendered infectious following cleavage of VP0 into VP4 and VP2. This maturation seems to be an autocatalytic event triggered by the presence of RNA in the capsid and is followed by a conformational change of the particle.
Protein VP1-2A
The assembly signal 2A is removed from VP1-2A by a host protease, possibly host Cathepsin L in naked virions. This cleavage does not occur in enveloped virions. This cleavage occurs over a region of 3 amino-acids probably generating VP1 proteins with heterogeneous C-termini.
Capsid protein VP4
Unlike other picornaviruses, does not seem to be myristoylated.
Interaction
Subunit
Protein VP1-2A
Homopentamer. Homooligomer.
Capsid protein VP1
Interacts with capsid protein VP2. Interacts with capsid protein VP3.
Capsid protein VP2
Interacts with capsid protein VP1. Interacts with capsid protein VP3.
Capsid protein VP3
Interacts with capsid protein VP1. Interacts with capsid protein VP2.
Family & Domains
Features
Showing features for region, motif.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Region | 34-55 | Disordered | ||||
Sequence: TAEVGSHQPEPLKTSVDKPGSK | ||||||
Motif | 146-150 | (L)YPX(n)L motif | ||||
Sequence: YPHGL | ||||||
Motif | 179-184 | (L)YPX(n)L motif | ||||
Sequence: YPVWEL |
Domain
Protein VP1-2A
The assembly signal 2A region mediates pentamerization of P1-2A.
Genome polyprotein
Late-budding domains (L domains) are short sequence motifs essential for viral particle budding. They recruit proteins of the host ESCRT machinery (Endosomal Sorting Complex Required for Transport) or ESCRT-associated proteins. The genome polyprotein contains two L domains: a tandem of (L)YPX(n)L domain which is known to bind the PDCD6IP/ALIX adaptater protein.
Capsid protein VP2
Late-budding domains (L domains) are short sequence motifs essential for viral particle budding. They recruit proteins of the host ESCRT machinery (Endosomal Sorting Complex Required for Transport) or ESCRT-associated proteins. Capsid protein VP2 contains two L domains: a tandem of (L)YPX(n)L domain which is known to bind the Alix adaptater protein.
Sequence similarities
Belongs to the picornaviridae polyprotein family.
Family and domain databases
Sequence
- Sequence statusFragment
- Length808
- Mass (Da)90,633
- Last updated1993-07-01 v1
- ChecksumD80CE7E57A479C12
Features
Showing features for non-terminal residue, sequence conflict.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Non-terminal residue | 1 | |||||
Sequence: L | ||||||
Sequence conflict | 763 | in Ref. 2 | ||||
Sequence: T → S | ||||||
Non-terminal residue | 808 | |||||
Sequence: K |