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UniProt functional annotation for P08617 | ||
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| UniProt code: P08617. |
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| Organism: | |
Human hepatitis A virus genotype IB (isolate HM175) (HHAV) (Human hepatitis A virus (isolate Human/Australia/HM175/1976)). |
| Taxonomy: | |
Viruses; Riboviria; Orthornavirae; Pisuviricota; Pisoniviricetes; Picornavirales; Picornaviridae; Hepatovirus. |
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| Function: | |
[Capsid protein VP1]: Capsid proteins VP1, VP2, and VP3 form a closed capsid enclosing the viral positive strand RNA genome (PubMed:25327248, PubMed:28074040). All these proteins contain a beta- sheet structure called beta-barrel jelly roll (PubMed:25327248). 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 (PubMed:25327248). VP1 is situated at the 12 fivefold axes, whereas VP2 and VP3 are located at the quasi-sixfold axes (PubMed:25327248). The naked capsid interacts with the host receptor HAVCR1 to provide virion attachment to and probably entry into the target cell (PubMed:9658108, PubMed:11134285, PubMed:29437974). {ECO:0000269|PubMed:11134285, ECO:0000269|PubMed:25327248, ECO:0000269|PubMed:28074040, ECO:0000269|PubMed:29437974, ECO:0000269|PubMed:9658108}. |
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| Function: | |
[Capsid protein VP2]: Capsid proteins VP1, VP2, and VP3 form a closed capsid enclosing the viral positive strand RNA genome (PubMed:25327248, PubMed:28074040). All these proteins contain a beta- sheet structure called beta-barrel jelly roll (PubMed:25327248). 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 (PubMed:25327248). VP1 is situated at the 12 fivefold axes, whereas VP2 and VP3 are located at the quasi-sixfold axes (PubMed:25327248). The naked capsid interacts with the host receptor HAVCR1 to provide virion attachment to and probably entry into the target cell (PubMed:9658108, PubMed:11134285, PubMed:29437974). {ECO:0000269|PubMed:11134285, ECO:0000269|PubMed:25327248, ECO:0000269|PubMed:28074040, ECO:0000269|PubMed:29437974, ECO:0000269|PubMed:9658108}. |
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| Function: | |
[Capsid protein VP3]: Capsid proteins VP1, VP2, and VP3 form a closed capsid enclosing the viral positive strand RNA genome (PubMed:25327248, PubMed:28074040). All these proteins contain a beta- sheet structure called beta-barrel jelly roll (PubMed:25327248). 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 (PubMed:25327248). VP1 is situated at the 12 fivefold axes, whereas VP2 and VP3 are located at the quasi-sixfold axes (PubMed:25327248). The naked capsid interacts with the host receptor HAVCR1 to provide virion attachment to and probably entry into the target cell (PubMed:9658108, PubMed:11134285, PubMed:29437974). {ECO:0000269|PubMed:11134285, ECO:0000269|PubMed:25327248, ECO:0000269|PubMed:28074040, ECO:0000269|PubMed:29437974, ECO:0000269|PubMed:9658108}. |
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| Function: | |
[Capsid protein VP0]: VP0 precursor is a component of the immature procapsids. {ECO:0000269|PubMed:25327248}. |
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| Function: | |
[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. {ECO:0000269|PubMed:9988685}. |
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| Function: | |
[Protein VP1-2A]: Precursor component of immature procapsids that corresponds to an extended form of the structural protein VP1 (PubMed:9988685, PubMed:12097562). After maturation, possibly by the host Cathepsin L, the assembly signal 2A is cleaved to give rise to the mature VP1 protein (PubMed:9988685). {ECO:0000269|PubMed:12097562, ECO:0000269|PubMed:9988685}. |
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| Function: | |
[Protein 2B]: Functions as a viroporin (PubMed:26515753). Affects membrane integrity and causes an increase in membrane permeability (PubMed:9875331). Involved in host intracellular membrane rearrangements probably to give rise to the viral factories (PubMed:9344908). Does not disrupt calcium homeostasis or glycoprotein trafficking (PubMed:18216106). Antagonizes the innate immune response of the host by suppressing IFN-beta synthesis, which it achieves by interfering with the DDX58/IFIH1 (RIG-I/MDA5) pathway (PubMed:18559929). {ECO:0000269|PubMed:18216106, ECO:0000269|PubMed:18559929, ECO:0000269|PubMed:26515753, ECO:0000269|PubMed:9344908, ECO:0000269|PubMed:9875331}. |
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| Function: | |
[Protein 2BC]: Affects membrane integrity and causes an increase in membrane permeability. {ECO:0000269|PubMed:9344908, ECO:0000269|PubMed:9875331}. |
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| Function: | |
[Protein 2C]: Associates with and induces structural rearrangements of intracellular membranes (PubMed:9344908). Displays RNA-binding activity (PubMed:9645199). {ECO:0000269|PubMed:9344908, ECO:0000269|PubMed:9645199}. |
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| Function: | |
[Protein 3ABC]: The precursor 3ABC is targeted to the mitochondrial membrane where protease 3C activity cleaves and inhibits the host antiviral protein MAVS, thereby disrupting activation of IRF3 through the IFIH1/MDA5 pathway (PubMed:17438296). In vivo, the protease activity of 3ABC precursor is more efficient in cleaving the 2BC precursor than that of protein 3C. The 3ABC precursor may therefore play a role in the proteolytic processing of the polyprotein (PubMed:10559299). {ECO:0000269|PubMed:10559299, ECO:0000269|PubMed:17438296}. |
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| Function: | |
[Protein 3AB]: Interacts with the 3CD precursor and with RNA structures found at both the 5'- and 3'-termini of the viral genome (PubMed:10562502). Since the 3AB precursor contains the hydrophobic domain 3A, it probably anchors the whole viral replicase complex to intracellular membranes on which viral RNA synthesis occurs (PubMed:9705870). {ECO:0000269|PubMed:10562502, ECO:0000269|PubMed:9705870}. |
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| Function: | |
[Protein 3A]: May serve as membrane anchor to the 3AB and 3ABC precursors via its hydrophobic domain (PubMed:9705870). May interact with RNA (PubMed:10562502). {ECO:0000269|PubMed:10562502, ECO:0000269|PubMed:9705870}. |
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| Function: | |
[Viral protein genome-linked]: Acts as a primer for viral RNA replication and remains covalently bound to viral genomic RNA. VPg is uridylylated prior to priming replication into VPg-pUpU. The VPg-pUpU is then used as primer on the genomic RNA poly(A) by the RNA-dependent RNA polymerase to replicate the viral genome. {ECO:0000250|UniProtKB:P03300, ECO:0000303|PubMed:25240314}. |
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| Function: | |
[Protease 3C]: Cysteine protease that generates mature viral proteins from the precursor polyprotein (PubMed:1850033). In addition to its proteolytic activity, it binds to viral RNA, and thus influences viral genome replication (PubMed:15361063). RNA and substrate bind cooperatively to the protease (PubMed:9032381). Cleaves IKBKG/NEMO to impair innate immune signaling (PubMed:24920812). Cleaves host PABPC1 which may participate in the switch of viral translation to RNA synthesis (PubMed:17726047). {ECO:0000269|PubMed:15361063, ECO:0000269|PubMed:17726047, ECO:0000269|PubMed:1850033, ECO:0000269|PubMed:24920812, ECO:0000269|PubMed:9032381}. |
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| Function: | |
[Protein 3CD]: Interacts with the 3AB precursor and with RNA structures found at both the 5'- and 3'-termini of the viral genome (PubMed:10562502). Disrupts TLR3 signaling by degrading the host adapter protein TICAM1/TRIF (PubMed:21931545). {ECO:0000269|PubMed:10562502, ECO:0000269|PubMed:21931545}. |
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| Function: | |
RNA-directed RNA polymerase 3D-POL replicates genomic and antigenomic RNA by recognizing replications specific signals. {ECO:0000305}. |
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| Catalytic activity: | |
Reaction=a ribonucleoside 5'-triphosphate + RNA(n) = diphosphate + RNA(n+1); Xref=Rhea:RHEA:21248, Rhea:RHEA-COMP:11128, Rhea:RHEA- COMP:11129, ChEBI:CHEBI:33019, ChEBI:CHEBI:61557, ChEBI:CHEBI:83400; EC=2.7.7.48; Evidence={ECO:0000255|PROSITE-ProRule:PRU00539, ECO:0000269|PubMed:8291234}; |
| Catalytic activity: | |
Reaction=a ribonucleoside 5'-triphosphate + H2O = a ribonucleoside 5'- diphosphate + H(+) + phosphate; Xref=Rhea:RHEA:23680, ChEBI:CHEBI:15377, ChEBI:CHEBI:15378, ChEBI:CHEBI:43474, ChEBI:CHEBI:57930, ChEBI:CHEBI:61557; EC=3.6.1.15; |
| Catalytic activity: | |
Reaction=Selective cleavage of Gln-|-Gly bond in the poliovirus polyprotein. In other picornavirus reactions Glu may be substituted for Gln, and Ser or Thr for Gly.; EC=3.4.22.28; Evidence={ECO:0000255|PROSITE-ProRule:PRU01222, ECO:0000269|PubMed:1850033}; |
| Subunit: | |
[Protein 2B]: Homodimer. Homomultimer; probably interacts with membranes in a multimeric form (PubMed:26515753). Seems to assemble into amyloid-like fibers (PubMed:25589659). {ECO:0000269|PubMed:25589659, ECO:0000269|PubMed:26515753, ECO:0000305}. |
| Subunit: | |
[Protein 3A]: Interacts with host ACBD3 (PubMed:23572552). {ECO:0000269|PubMed:23572552}. |
| Subunit: | |
[Protein 3AB]: Homodimer. Monomer (PubMed:9705870). Interacts with protein 3CD (PubMed:10562502). {ECO:0000269|PubMed:10562502, ECO:0000269|PubMed:9705870, ECO:0000305}. |
| Subunit: | |
[Protein 3CD]: Interacts with protein 3AB (PubMed:10562502). {ECO:0000269|PubMed:10562502}. |
| Subunit: | |
[Protein 3ABC]: Interacts with human MAVS (PubMed:17438296). {ECO:0000269|PubMed:17438296}. |
| Subunit: | |
[Protease 3C]: Homodimer; disulfide-linked (PubMed:15361063). {ECO:0000269|PubMed:15361063}. |
| Subunit: | |
[Protein VP1-2A]: Homopentamer (PubMed:12782637). Homooligomer (PubMed:18823593, PubMed:12782637). {ECO:0000269|PubMed:12782637, ECO:0000269|PubMed:18823593}. |
| Subunit: | |
[Capsid protein VP1]: Interacts with capsid protein VP2 (PubMed:25327248, PubMed:28074040). Interacts with capsid protein VP3 (PubMed:25327248, PubMed:28074040). {ECO:0000269|PubMed:25327248}. |
| Subunit: | |
[Capsid protein VP2]: Interacts with capsid protein VP1 (PubMed:25327248, PubMed:28074040). Interacts with capsid protein VP3 (PubMed:25327248, PubMed:28074040). {ECO:0000269|PubMed:25327248}. |
| Subunit: | |
[Capsid protein VP3]: Interacts with capsid protein VP1 (PubMed:25327248, PubMed:28074040). Interacts with capsid protein VP2 (PubMed:25327248, PubMed:28074040). {ECO:0000269|PubMed:25327248}. |
| Subcellular location: | |
[Capsid protein VP2]: Virion {ECO:0000269|PubMed:25327248, ECO:0000269|PubMed:28074040}. Host endosome, host multivesicular body {ECO:0000269|PubMed:28490497}. Note=The egress of newly formed virions occurs through an exosome-like mechanism involving endosomal budding of viral capsids into multivesicular bodies. {ECO:0000269|PubMed:28490497}. |
| Subcellular location: | |
[Capsid protein VP3]: Virion {ECO:0000269|PubMed:25327248, ECO:0000269|PubMed:28074040}. Host endosome, host multivesicular body {ECO:0000269|PubMed:28490497}. Note=The egress of newly formed virions occurs through an exosome-like mechanism involving endosomal budding of viral capsids into multivesicular bodies. {ECO:0000269|PubMed:28490497}. |
| Subcellular location: | |
[Capsid protein VP1]: Virion {ECO:0000269|PubMed:25327248, ECO:0000269|PubMed:28074040}. Host endosome, host multivesicular body {ECO:0000269|PubMed:28490497}. Note=The egress of newly formed virions occurs through an exosome-like mechanism involving endosomal budding of viral capsids into multivesicular bodies. {ECO:0000269|PubMed:28490497}. |
| Subcellular location: | |
[Capsid protein VP4]: Virion {ECO:0000269|PubMed:25327248}. Note=Present in the full mature virion (PubMed:25327248). The egress of newly formed virions occurs through an exosome-like mechanism involving endosomal budding of viral capsids into multivesicular bodies (Probable). {ECO:0000269|PubMed:25327248, ECO:0000305|PubMed:28490497}. |
| Subcellular location: | |
[Protein 2B]: Host membrane {ECO:0000269|PubMed:18216106, ECO:0000269|PubMed:26515753, ECO:0000269|PubMed:9875331}; Peripheral membrane protein {ECO:0000269|PubMed:9875331}. Note=Probably localizes to intracellular membrane vesicles that are induced after virus infection as the site for viral RNA replication. {ECO:0000305}. |
| Subcellular location: | |
[Protein 2C]: Host membrane {ECO:0000269|PubMed:9645199}; Single-pass membrane protein {ECO:0000269|PubMed:9875331}. Note=Probably localizes to intracellular membrane vesicles that are induced after virus infection as the site for viral RNA replication. May associate with membranes through a N- terminal amphipathic helix. {ECO:0000305|PubMed:9645199}. |
| Subcellular location: | |
[Protein 3ABC]: Host membrane {ECO:0000305}; Single-pass membrane protein {ECO:0000255}. Host mitochondrion outer membrane {ECO:0000269|PubMed:17438296}; Single-pass membrane protein {ECO:0000305}. Note=Probably localizes to intracellular membrane vesicles that are induced after virus infection as the site for viral RNA replication. {ECO:0000305}. |
| Subcellular location: | |
[Protein 3AB]: Host membrane {ECO:0000305}; Single-pass membrane protein {ECO:0000255}. Note=Probably localizes to intracellular membrane vesicles that are induced after virus infection as the site for viral RNA replication. {ECO:0000305}. |
| Subcellular location: | |
[Protein 3A]: Host membrane {ECO:0000305}; Single-pass membrane protein {ECO:0000255}. Note=Probably localizes to intracellular membrane vesicles that are induced after virus infection as the site for viral RNA replication. {ECO:0000305}. |
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[Viral protein genome-linked]: Virion {ECO:0000305}. |
| Subcellular location: | |
[Protease 3C]: Host cytoplasm {ECO:0000305}. |
| Subcellular location: | |
[RNA-directed RNA polymerase 3D-POL]: Host cytoplasmic vesicle membrane {ECO:0000305}; Peripheral membrane protein {ECO:0000305}; Cytoplasmic side {ECO:0000305}. Note=Interacts with membranes in a complex with viral protein 3AB. Probably localizes to the surface of intracellular membrane vesicles that are induced after virus infection as the site for viral RNA replication. These vesicles are derived from the endoplasmic reticulum. {ECO:0000305}. |
| Domain: | |
[Protein VP1-2A]: The assembly signal 2A region mediates pentamerization of P1-2A. {ECO:0000269|PubMed:12097562, ECO:0000269|PubMed:12782637}. |
| Domain: | |
[Genome polyprotein]: Late-budding domains (L domains) are short sequence motifs essential for viral particle budding (Probable). They recruit proteins of the host ESCRT machinery (Endosomal Sorting Complex Required for Transport) or ESCRT-associated proteins (Probable). 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 (PubMed:23542590). {ECO:0000269|PubMed:23542590, ECO:0000305}. |
| Domain: | |
[Capsid protein VP2]: Late-budding domains (L domains) are short sequence motifs essential for viral particle budding (Probable). They recruit proteins of the host ESCRT machinery (Endosomal Sorting Complex Required for Transport) or ESCRT-associated proteins (Probable). Capsid protein VP2 contains two L domains: a tandem of (L)YPX(n)L domain which is known to bind the Alix adaptater protein (PubMed:23542590). {ECO:0000269|PubMed:23542590, ECO:0000305}. |
| Domain: | |
[Protein 2B]: The C-terminus displays a membrane-penetrating ability. {ECO:0000269|PubMed:26515753}. |
| Ptm: | |
[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 (PubMed:7483265, PubMed:1850033, PubMed:8382411, PubMed:8291234, PubMed:9060697, PubMed:9733840, PubMed:8259663, PubMed:7853510, PubMed:10559299). The assembly signal 2A is removed from VP1-2A by a host protease, possibly host Cathepsin L (PubMed:18823593). This cleavage occurs over a region of 3 amino-acids probably generating VP1 proteins with heterogeneous C-termini (PubMed:10364353). {ECO:0000269|PubMed:10364353, ECO:0000269|PubMed:10559299, ECO:0000269|PubMed:1850033, ECO:0000269|PubMed:18823593, ECO:0000269|PubMed:7483265, ECO:0000269|PubMed:7853510, ECO:0000269|PubMed:8259663, ECO:0000269|PubMed:8291234, ECO:0000269|PubMed:8382411, ECO:0000269|PubMed:9060697, ECO:0000269|PubMed:9733840}. |
| Ptm: | |
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 (PubMed:12782637, PubMed:8291234, PubMed:9060697, PubMed:9733840). {ECO:0000269|PubMed:12782637, ECO:0000269|PubMed:8291234, ECO:0000269|PubMed:9060697, ECO:0000269|PubMed:9733840}. |
| Ptm: | |
[Protein VP1-2A]: The assembly signal 2A is removed from VP1-2A by a host protease, possibly host Cathepsin L in nacked virions (PubMed:18823593). This cleavage does not occur in enveloped virions (PubMed:28490497). This cleavage occurs over a region of 3 amino-acids probably generating VP1 proteins with heterogeneous C-termini (PubMed:10364353). {ECO:0000269|PubMed:10364353, ECO:0000269|PubMed:18823593, ECO:0000269|PubMed:28490497}. |
| Ptm: | |
[Viral protein genome-linked]: VPg is uridylylated prior to priming replication into VPg-pUpU. {ECO:0000250|UniProtKB:P03300}. |
| Ptm: | |
[Capsid protein VP4]: Unlike other picornaviruses, does not seem to be myristoylated. {ECO:0000269|PubMed:8389076}. |
| Miscellaneous: | |
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. {ECO:0000305}. |
| Miscellaneous: | |
During infection, enveloped virions (eHAV) are released from cells (PubMed:23542590). These eHAV are cloaked in host-derived membranes and resemble exosomes (PubMed:28490497). The membrane of eHAV is devoid of viral proteins and thus prevents their neutralization by antibodies (PubMed:23542590). eHAV budding is dependent on ESCRT- associated proteins VPS4B and PDCD6IP/ALIX (PubMed:23542590). eHAV are produced and released in the serum and plasma, but not in bile and feces which only contain the naked, nonenveloped virions (Probable). It is likely that eHAV also use HAVCR1 as a functional receptor to infect cells, an evolutionary trait that may enhance HAV infectivity (PubMed:29437974). {ECO:0000269|PubMed:23542590, ECO:0000269|PubMed:28490497, ECO:0000269|PubMed:29437974, ECO:0000303|PubMed:23542590, ECO:0000305}. |
| Miscellaneous: | |
Wild-type HM175 (HM175/wt) comes from a sample isolated from a patient in Australia in 1976 and subsequently passaged three times in marmosets. HM175/7 is an attenuated strain derived from HM175 by 32 passages in African green monkey kidney cells. HM175/18f, HM175/24a, and HM175/43c are cytopathic isolates derived from HM175 by serial passages in FRhK-4 cells. {ECO:0000305}. |
| Miscellaneous: | |
Mutations in proteins 2B and 2C seem to be essential for strain HM175 adaptation to growth in cell culture. |
| Similarity: | |
Belongs to the picornaviridae polyprotein family. {ECO:0000305}. |
| Sequence caution: | |
Sequence=AAA45466.1; Type=Erroneous initiation; Evidence={ECO:0000305}; |
Annotations taken from UniProtKB at the EBI.