P25219 · POLS_IBDV5
- ProteinStructural polyprotein
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids1012 (go to sequence)
- Protein existenceInferred from homology
- Annotation score5/5
Function
function
Capsid protein VP2 self assembles to form an icosahedral capsid with a T=13 symmetry, about 70 nm in diameter, and consisting of 260 VP2 trimers. The capsid encapsulates the genomic dsRNA. VP2 is also involved in attachment and entry into the host cell by interacting with host ITGA4/ITGB1 (By similarity).
The precursor of VP2 plays an important role in capsid assembly. First, pre-VP2 and VP2 oligomers assemble to form a procapsid. Then, the pre-VP2 intermediates may be processed into VP2 proteins by proteolytic cleavage mediated by VP4 to obtain the mature virion. The final capsid is composed of pentamers and hexamers but VP2 has a natural tendency to assemble into all-pentameric structures. Therefore pre-VP2 may be required to allow formation of the hexameric structures (By similarity).
Protease VP4 is a serine protease that cleaves the polyprotein into its final products. Pre-VP2 is first partially cleaved, and may be completely processed by VP4 upon capsid maturation.
Capsid protein VP3 plays a key role in virion assembly by providing a scaffold for the capsid made of VP2. May self-assemble to form a T=4-like icosahedral inner-capsid composed of at least 180 trimers. Plays a role in genomic RNA packaging by recruiting VP1 into the capsid and interacting with the dsRNA genome segments to form a ribonucleoprotein complex. Additionally, the interaction of the VP3 C-terminal tail with VP1 removes the inherent structural blockade of the polymerase active site. Thus, VP3 can also function as a transcriptional activator (By similarity).
Structural peptide 1 is a small peptide derived from pre-VP2 C-terminus. It destabilizes and perforates cell membranes, suggesting a role during entry (By similarity).
Structural peptide 2 is a small peptide derived from pVP2 C-terminus. It is not essential for the virus viability, but viral growth is affected when missing (By similarity).
Structural peptide 3 is a small peptide derived from pVP2 C-terminus. It is not essential for the virus viability, but viral growth is affected when missing (By similarity).
Structural peptide 4 is a small peptide derived from pVP2 C-terminus. It is essential for the virus viability (By similarity).
Features
Showing features for binding site, site, active site.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Binding site | 30 | a divalent metal cation (UniProtKB | ChEBI); ligand shared between trimeric partners | ||||
Sequence: D | ||||||
Site | 441-442 | Cleavage; by protease VP4 | ||||
Sequence: AF | ||||||
Site | 487-488 | Cleavage; by protease VP4 | ||||
Sequence: AA | ||||||
Site | 494-495 | Cleavage; by protease VP4 | ||||
Sequence: AA | ||||||
Site | 501-502 | Cleavage; by protease VP4 | ||||
Sequence: AA | ||||||
Site | 512-513 | Cleavage; by protease VP4 | ||||
Sequence: AA | ||||||
Active site | 652 | Nucleophile | ||||
Sequence: S | ||||||
Active site | 692 | |||||
Sequence: K | ||||||
Site | 755-756 | Cleavage; by protease VP4 | ||||
Sequence: AA |
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | host cell cytoplasm | |
Cellular Component | T=13 icosahedral viral capsid | |
Molecular Function | metal ion binding | |
Molecular Function | serine-type peptidase activity | |
Molecular Function | structural molecule activity | |
Biological Process | proteolysis |
Keywords
- Molecular function
- Ligand
Protein family/group databases
Names & Taxonomy
Protein names
- Recommended nameStructural polyprotein
- Short namesPP
- Cleaved into 8 chains
Organism names
- Taxonomic lineageViruses > Riboviria > Orthornavirae > Birnaviridae > Avibirnavirus > Avibirnavirus gumboroense
- Virus hosts
Accessions
- Primary accessionP25219
Subcellular Location
UniProt Annotation
GO Annotation
Capsid protein VP2
Capsid protein VP3
Structural peptide 1
Structural peptide 2
Structural peptide 3
Structural peptide 4
Keywords
- Cellular component
PTM/Processing
Features
Showing features for chain, peptide.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Chain | PRO_0000036759 | 1-441 | Capsid protein VP2 | |||
Sequence: MTNLQDQTQQIVPFIRSLLMPTTGPASIPDDTLEKHTLRSETSTYNLTVGDTGSGLIVFFPGFPGSIVGAHYTLQSNGNYKFDQMLLTAQNLPASYNYCRLVSRSLTVRSSTLPGGVYALNGTINAVTFQGSLSELTDVSYNGLMSATANINDKIGNVLVGEGVTVLSLPTSYDLGYVRLGDPIPAIGLDPKMVATCDSSDRPRVYTITAADDYQFSSQYQPGGVTITLFSANIDAITSLSIGGELVFQTSVQGLVLGATIYLIGFDGTAVITRAVAADNGLTAGTDNLMPFNLVIPTNEITQPITSIKLEIVTSKSGGQAGDQMSWSASGSLAVTIHGGNYPGALRPVTLVAYERVATGSVVTVAGVSNFELIPNPELAKNLVTEYGRFDPGAMNYTKLILSERDRLGIKTVWPTREYTDFREYFMEVADLNSPLKIAGA | ||||||
Chain | PRO_0000392585 | 1-512 | Precursor of VP2 | |||
Sequence: MTNLQDQTQQIVPFIRSLLMPTTGPASIPDDTLEKHTLRSETSTYNLTVGDTGSGLIVFFPGFPGSIVGAHYTLQSNGNYKFDQMLLTAQNLPASYNYCRLVSRSLTVRSSTLPGGVYALNGTINAVTFQGSLSELTDVSYNGLMSATANINDKIGNVLVGEGVTVLSLPTSYDLGYVRLGDPIPAIGLDPKMVATCDSSDRPRVYTITAADDYQFSSQYQPGGVTITLFSANIDAITSLSIGGELVFQTSVQGLVLGATIYLIGFDGTAVITRAVAADNGLTAGTDNLMPFNLVIPTNEITQPITSIKLEIVTSKSGGQAGDQMSWSASGSLAVTIHGGNYPGALRPVTLVAYERVATGSVVTVAGVSNFELIPNPELAKNLVTEYGRFDPGAMNYTKLILSERDRLGIKTVWPTREYTDFREYFMEVADLNSPLKIAGAFGFKDIIRAIRRIAVPVVSTLFPPAAPLAHAIGEGVDYLLGDEAQAASGTARAASGKARAASGRIRQLTLA | ||||||
Chain | PRO_0000392584 | 1-1012 | Structural polyprotein | |||
Sequence: MTNLQDQTQQIVPFIRSLLMPTTGPASIPDDTLEKHTLRSETSTYNLTVGDTGSGLIVFFPGFPGSIVGAHYTLQSNGNYKFDQMLLTAQNLPASYNYCRLVSRSLTVRSSTLPGGVYALNGTINAVTFQGSLSELTDVSYNGLMSATANINDKIGNVLVGEGVTVLSLPTSYDLGYVRLGDPIPAIGLDPKMVATCDSSDRPRVYTITAADDYQFSSQYQPGGVTITLFSANIDAITSLSIGGELVFQTSVQGLVLGATIYLIGFDGTAVITRAVAADNGLTAGTDNLMPFNLVIPTNEITQPITSIKLEIVTSKSGGQAGDQMSWSASGSLAVTIHGGNYPGALRPVTLVAYERVATGSVVTVAGVSNFELIPNPELAKNLVTEYGRFDPGAMNYTKLILSERDRLGIKTVWPTREYTDFREYFMEVADLNSPLKIAGAFGFKDIIRAIRRIAVPVVSTLFPPAAPLAHAIGEGVDYLLGDEAQAASGTARAASGKARAASGRIRQLTLAADKGYEVVANLFQVPQNPVVDGILASPGVLRGAHNLDCVLREGATLFPVVITTVEDAMTPKALNSKMFAVIEGVREDLQPPSQRGSFIRTLSGHRVYGYAPDGVLPLETGRDYTVVPIDDVWDDSIMLSKDPIPPIVGNSGNLAIAYMDVFRPKVPIHVAMTGAPNACGEIEKISFRSTKLATAHRLGLKLAGPGAFDVNTGPNWATFIKRFPHNPRDWDRLPYLNLPYLPPNAGRQYHLAMAASEFKDTPELESAVRAMEAAANVDSLFQSALSVFMWLEENGIVTDMANFTLSDPNAHRMRNFLANAPQAGSKSQRAKYGTAGYGVEARGPTPEEAQRKKDTRISKKMETMGIYFATPEWVALNGHRGPSPGQLKYWQNTREIPDPNEDYLDYVHAEKSRLASDEQILRAATSIYGAPGQAEPPQAFIDEVAKVYEINHGRGPNQEQMKDLLLTAMEMKHRNPRRAPPKPKPKPNAPTQRPPGRLGRWIRTVSDEDLE | ||||||
Peptide | PRO_0000227823 | 442-487 | Structural peptide 1 | |||
Sequence: FGFKDIIRAIRRIAVPVVSTLFPPAAPLAHAIGEGVDYLLGDEAQA | ||||||
Peptide | PRO_0000227824 | 488-494 | Structural peptide 2 | |||
Sequence: ASGTARA | ||||||
Peptide | PRO_0000227825 | 495-501 | Structural peptide 3 | |||
Sequence: ASGKARA | ||||||
Peptide | PRO_0000227826 | 502-512 | Structural peptide 4 | |||
Sequence: ASGRIRQLTLA | ||||||
Chain | PRO_0000036760 | 513-755 | Protease VP4 | |||
Sequence: ADKGYEVVANLFQVPQNPVVDGILASPGVLRGAHNLDCVLREGATLFPVVITTVEDAMTPKALNSKMFAVIEGVREDLQPPSQRGSFIRTLSGHRVYGYAPDGVLPLETGRDYTVVPIDDVWDDSIMLSKDPIPPIVGNSGNLAIAYMDVFRPKVPIHVAMTGAPNACGEIEKISFRSTKLATAHRLGLKLAGPGAFDVNTGPNWATFIKRFPHNPRDWDRLPYLNLPYLPPNAGRQYHLAMA | ||||||
Chain | PRO_0000036761 | 756-1012 | Capsid protein VP3 | |||
Sequence: ASEFKDTPELESAVRAMEAAANVDSLFQSALSVFMWLEENGIVTDMANFTLSDPNAHRMRNFLANAPQAGSKSQRAKYGTAGYGVEARGPTPEEAQRKKDTRISKKMETMGIYFATPEWVALNGHRGPSPGQLKYWQNTREIPDPNEDYLDYVHAEKSRLASDEQILRAATSIYGAPGQAEPPQAFIDEVAKVYEINHGRGPNQEQMKDLLLTAMEMKHRNPRRAPPKPKPKPNAPTQRPPGRLGRWIRTVSDEDLE |
Post-translational modification
Specific enzymatic cleavages yield mature proteins. The capsid assembly seems to be regulated by polyprotein processing. The protease VP4 cleaves itself off the polyprotein, thus releasing pre-VP2 and VP3 within the infected cell. During capsid assembly, the C-terminus of pre-VP2 is further processed by VP4, giving rise to VP2, the external capsid protein and three small peptides that all stay closely associated with the capsid (By similarity).
Interaction
Subunit
Capsid protein VP2
Homotrimer. A central divalent metal stabilizes the VP2 trimer (By similarity).
Interacts with host ITGA4/ITGB1
Interacts with host ITGA4/ITGB1
Capsid protein VP3
Homodimer. Interacts (via C-terminus) with VP1 in the cytoplasm. Interacts with VP2 (By similarity).
Family & Domains
Features
Showing features for domain, region.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Domain | 513-755 | Peptidase S50 | ||||
Sequence: ADKGYEVVANLFQVPQNPVVDGILASPGVLRGAHNLDCVLREGATLFPVVITTVEDAMTPKALNSKMFAVIEGVREDLQPPSQRGSFIRTLSGHRVYGYAPDGVLPLETGRDYTVVPIDDVWDDSIMLSKDPIPPIVGNSGNLAIAYMDVFRPKVPIHVAMTGAPNACGEIEKISFRSTKLATAHRLGLKLAGPGAFDVNTGPNWATFIKRFPHNPRDWDRLPYLNLPYLPPNAGRQYHLAMA | ||||||
Region | 837-857 | Disordered | ||||
Sequence: GYGVEARGPTPEEAQRKKDTR | ||||||
Region | 968-1012 | Disordered | ||||
Sequence: TAMEMKHRNPRRAPPKPKPKPNAPTQRPPGRLGRWIRTVSDEDLE | ||||||
Region | 1003-1012 | Interaction with VP1 protein | ||||
Sequence: IRTVSDEDLE |
Family and domain databases
Sequence
- Sequence statusComplete
- Length1,012
- Mass (Da)109,568
- Last updated1992-05-01 v1
- Checksum71A5D93A064DB36D