P25219 · POLS_IBDV5

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.

TypeIDPosition(s)Description
Binding site30a divalent metal cation (UniProtKB | ChEBI); ligand shared between trimeric partners
Site441-442Cleavage; by protease VP4
Site487-488Cleavage; by protease VP4
Site494-495Cleavage; by protease VP4
Site501-502Cleavage; by protease VP4
Site512-513Cleavage; by protease VP4
Active site652Nucleophile
Active site692
Site755-756Cleavage; by protease VP4

GO annotations

AspectTerm
Cellular Componenthost cell cytoplasm
Cellular ComponentT=13 icosahedral viral capsid
Molecular Functionmetal ion binding
Molecular Functionserine-type peptidase activity
Molecular Functionstructural molecule activity
Biological Processproteolysis

Keywords

Protein family/group databases

Names & Taxonomy

Protein names

Organism names

Accessions

  • Primary accession
    P25219

Subcellular Location

Capsid protein VP2

Virion

Capsid protein VP3

Virion

Structural peptide 1

Virion

Structural peptide 2

Virion

Structural peptide 3

Virion

Structural peptide 4

Virion

Keywords

PTM/Processing

Features

Showing features for chain, peptide.

TypeIDPosition(s)Description
ChainPRO_00000367591-441Capsid protein VP2
ChainPRO_00003925851-512Precursor of VP2
ChainPRO_00003925841-1012Structural polyprotein
PeptidePRO_0000227823442-487Structural peptide 1
PeptidePRO_0000227824488-494Structural peptide 2
PeptidePRO_0000227825495-501Structural peptide 3
PeptidePRO_0000227826502-512Structural peptide 4
ChainPRO_0000036760513-755Protease VP4
ChainPRO_0000036761756-1012Capsid protein VP3

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

Capsid protein VP3

Homodimer. Interacts (via C-terminus) with VP1 in the cytoplasm. Interacts with VP2 (By similarity).

Structure

Family & Domains

Features

Showing features for domain, region.

TypeIDPosition(s)Description
Domain513-755Peptidase S50
Region837-857Disordered
Region968-1012Disordered
Region1003-1012Interaction with VP1 protein

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    1,012
  • Mass (Da)
    109,568
  • Last updated
    1992-05-01 v1
  • Checksum
    71A5D93A064DB36D
MTNLQDQTQQIVPFIRSLLMPTTGPASIPDDTLEKHTLRSETSTYNLTVGDTGSGLIVFFPGFPGSIVGAHYTLQSNGNYKFDQMLLTAQNLPASYNYCRLVSRSLTVRSSTLPGGVYALNGTINAVTFQGSLSELTDVSYNGLMSATANINDKIGNVLVGEGVTVLSLPTSYDLGYVRLGDPIPAIGLDPKMVATCDSSDRPRVYTITAADDYQFSSQYQPGGVTITLFSANIDAITSLSIGGELVFQTSVQGLVLGATIYLIGFDGTAVITRAVAADNGLTAGTDNLMPFNLVIPTNEITQPITSIKLEIVTSKSGGQAGDQMSWSASGSLAVTIHGGNYPGALRPVTLVAYERVATGSVVTVAGVSNFELIPNPELAKNLVTEYGRFDPGAMNYTKLILSERDRLGIKTVWPTREYTDFREYFMEVADLNSPLKIAGAFGFKDIIRAIRRIAVPVVSTLFPPAAPLAHAIGEGVDYLLGDEAQAASGTARAASGKARAASGRIRQLTLAADKGYEVVANLFQVPQNPVVDGILASPGVLRGAHNLDCVLREGATLFPVVITTVEDAMTPKALNSKMFAVIEGVREDLQPPSQRGSFIRTLSGHRVYGYAPDGVLPLETGRDYTVVPIDDVWDDSIMLSKDPIPPIVGNSGNLAIAYMDVFRPKVPIHVAMTGAPNACGEIEKISFRSTKLATAHRLGLKLAGPGAFDVNTGPNWATFIKRFPHNPRDWDRLPYLNLPYLPPNAGRQYHLAMAASEFKDTPELESAVRAMEAAANVDSLFQSALSVFMWLEENGIVTDMANFTLSDPNAHRMRNFLANAPQAGSKSQRAKYGTAGYGVEARGPTPEEAQRKKDTRISKKMETMGIYFATPEWVALNGHRGPSPGQLKYWQNTREIPDPNEDYLDYVHAEKSRLASDEQILRAATSIYGAPGQAEPPQAFIDEVAKVYEINHGRGPNQEQMKDLLLTAMEMKHRNPRRAPPKPKPKPNAPTQRPPGRLGRWIRTVSDEDLE

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
D00869
EMBL· GenBank· DDBJ
BAA00745.1
EMBL· GenBank· DDBJ
Genomic RNA

Similar Proteins

Disclaimer

Any medical or genetic information present in this entry is provided for research, educational and informational purposes only. It is not in any way intended to be used as a substitute for professional medical advice, diagnosis, treatment or care. Our staff consists of biologists and biochemists that are not trained to give medical advice.
We'd like to inform you that we have updated our Privacy Notice to comply with Europe’s new General Data Protection Regulation (GDPR) that applies since 25 May 2018.
FeedbackHelp