Q2HRB6 · SCAF_HHV8P

Function

function

Capsid scaffolding protein

Acts as a scaffold protein by binding major capsid protein in the cytoplasm, inducing the nuclear localization of both proteins. Multimerizes in the nucleus such as major capsid protein forms the icosahedral T=16 capsid. Autocatalytic cleavage releases the assembly protein, and subsequently abolishes interaction with major capsid protein. Cleavages products are evicted from the capsid before or during DNA packaging.

Assemblin

Protease that plays an essential role in virion assembly within the nucleus. Catalyzes the cleavage of the assembly protein after formation of the spherical procapsid. By that cleavage, the capsid matures and gains its icosahedral shape. The cleavage sites seem to include -Ala-Ser-, -Ala-Ala-, as well as Ala-Thr bonds. Assemblin and cleavages products are evicted from the capsid before or during DNA packaging.

Assembly protein

Plays a major role in capsid assembly. Acts as a scaffold protein by binding major capsid protein. Multimerizes in the nucleus such as major capsid protein forms the icosahedral T=16 capsid. Cleaved by assemblin after capsid completion. The cleavages products are evicted from the capsid before or during DNA packaging.

Catalytic activity

  • Assemblin

    Cleaves -Ala-|-Ser- and -Ala-|-Ala- bonds in the scaffold protein.
    EC:3.4.21.97 (UniProtKB | ENZYME | Rhea)

Features

Showing features for active site, site.

TypeIDPosition(s)Description
Active site46Charge relay system
Active site114Charge relay system
Active site134Charge relay system
Site230-231Cleavage; by assemblin; Release site
Site512-513Cleavage; by assemblin; Maturation site

GO annotations

AspectTerm
Cellular Componenthost cell cytoplasm
Cellular Componenthost cell nucleus
Molecular Functionidentical protein binding
Molecular Functionserine-type endopeptidase activity
Biological Processnuclear capsid assembly
Biological Processproteolysis
Biological Processviral release from host cell

Keywords

Protein family/group databases

Names & Taxonomy

Protein names

  • Recommended name
    Capsid scaffolding protein
  • Alternative names
    • Capsid protein P40
    • Protease precursor
      (pPR
      )
  • Cleaved into 2 chains
    • Assemblin
      (EC:3.4.21.97 (UniProtKB | ENZYME | Rhea)
      ) Alternative names: Protease
      (Pr
      )
    • Assembly protein
      (AP
      ) Alternative names: Capsid assembly protein

Gene names

    • Name
      ORF17

Organism names

Accessions

  • Primary accession
    Q2HRB6
  • Secondary accessions
    • D0UZM9
    • O36607
    • Q2HRB5

Proteomes

Subcellular Location

Capsid scaffolding protein

Host cytoplasm

Assemblin

Host nucleus

Assembly protein

Host nucleus

Keywords

Phenotypes & Variants

Features

Showing features for mutagenesis.

TypeIDPosition(s)Description
Mutagenesis114Reduced levels of autoproteolysis.

Chemistry

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_00004358781-230Assemblin
ChainPRO_00004238791-534Capsid scaffolding protein
ChainPRO_0000435879231-534Assembly protein

Post-translational modification

Capsid scaffolding protein

Capsid scaffolding protein is cleaved by assemblin after formation of the spherical procapsid. As a result, the capsid obtains its mature, icosahedral shape. Cleavages occur at two or more sites: release (R-site) and maturation (M-site).

Keywords

Expression

Induction

Assembly protein

Expression is strongly up-regulated upon lytic induction of the virus.

Interaction

Subunit

Capsid scaffolding protein

Homomultimer. Interacts with major capsid protein.

Assemblin

Exists in a monomer-dimer equilibrium with the dimer being the active species.

Assembly protein

Homomultimer. Interacts with major capsid protein.

Protein-protein interaction databases

Structure

Family & Domains

Features

Showing features for region, motif, compositional bias.

TypeIDPosition(s)Description
Region253-272Interaction with pAP
Motif336-342Nuclear localization signal
Region337-356Disordered
Compositional bias338-356Basic and acidic residues
Region466-524Disordered
Compositional bias472-490Polar residues
Compositional bias501-515Polar residues
Region514-534Interaction with major capsid protein

Domain

Region of interaction between pPR and pAP is called Amino conserved domain (ACD). The region of interaction with major capsid protein is called carboxyl conserved domain (CCD).

Sequence similarities

Belongs to the herpesviridae capsid scaffolding protein family.

Family and domain databases

Sequence & Isoform

Align isoforms (2)
  • Sequence status
    Complete

This entry describes 2 isoforms produced by Alternative promoter usage.

Q2HRB6-1

This isoform has been chosen as the canonical sequence. All positional information in this entry refers to it. This is also the sequence that appears in the downloadable versions of the entry.

  • Name
    Capsid scaffolding protein
  • Synonyms
    pPR
  • See also
    sequence in UniParc or sequence clusters in UniRef
  • Length
    534
  • Mass (Da)
    57,866
  • Last updated
    2006-03-21 v1
  • Checksum
    EEA75DF8146B0791
MAQGLYVGGFVDVVSCPKLEQELYLDPDQVTDYLPVTEPLPITIEHLPETEVGWTLGLFQVSHGIFCTGAITSPAFLELASRLADTSHVARAPVKNLPKEPLLEILHTWLPGLSLSSIHPRELSQTPSGPVFQHVSLCALGRRRGTVAVYGHDAEWVVSRFSSVSKSERAHILQHVSSCRLEDLSTPNFVSPLETLMAKAIDASFIRDRLDLLKTDRGVASILSPAYLKASQFPVGIQAVTPPRPAMNSSGQEDIISIPKSAFLSMLQSSIDGMKTTAAKMSHTLSGPGLMGCGGQMFPTDHHLPSYVSNPAPPYGYAYKNPYDPWYYSPQLPGYRTGKRKRGAEDDEGHLFPGEEPAYHKDILSMSKNIAEIQSELKEMKLNGWHAGPPPSSSAAAAAVDPHYRPHANSAAPCQFPTMKEHGGTYVHPPIYVQAPHGQFQQAAPILFAQPHVSHPPVSTGLAVVGAPPAEPTPASSTQSIQQQAPETTHTPCAAVEKDAPTPNPTSNRVEASSRSSPKSKIRKMFCEELLNKQ

Q2HRB6-2

  • Name
    pAP
  • Synonyms
    Assembly protein
  • See also
    sequence in UniParc or sequence clusters in UniRef
  • Differences from canonical

Features

Showing features for alternative sequence, sequence conflict, compositional bias.

TypeIDPosition(s)Description
Alternative sequenceVSP_0532721-246in isoform pAP
Sequence conflict226in Ref. 1; AAC05223
Sequence conflict235in Ref. 1; AAC05223
Compositional bias338-356Basic and acidic residues
Compositional bias472-490Polar residues
Compositional bias501-515Polar residues
Sequence conflict510in Ref. 1; AAC05223
Sequence conflict529in Ref. 1; AAC05223

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
AF010430
EMBL· GenBank· DDBJ
AAC05223.1
EMBL· GenBank· DDBJ
Genomic DNA
AF148805
EMBL· GenBank· DDBJ
ABD28867.1
EMBL· GenBank· DDBJ
Genomic DNA
AF148805
EMBL· GenBank· DDBJ
ABD28868.1
EMBL· GenBank· DDBJ
Genomic DNA

Genome annotation databases

Similar Proteins

Disclaimer

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