A0A2K8HV90 · A0A2K8HV90_9CAUD
- ProteinTerminase, large subunit
- StatusUniProtKB unreviewed (TrEMBL)
- Organism
- Amino acids438 (go to sequence)
- Protein existenceInferred from homology
- Annotation score3/5
Function
function
The terminase large subunit acts as an ATP driven molecular motor necessary for viral DNA translocation into empty capsids and as an endonuclease that cuts the viral genome to initiate and to end a packaging reaction. The terminase lies at a unique vertex of the procapsid and is composed of two subunits, a small terminase subunit involved in viral DNA recognition (packaging sequence), and a large terminase subunit possessing endonucleolytic and ATPase activities. Both terminase subunits heterooligomerize and are docked on the portal protein to form the packaging machine. The terminase large subunit exhibits endonuclease activity and cleaves the viral genome concatemer. Once the capsid is packaged with the DNA, the terminase complex is substituted by the tail.
Cofactor
Note: ATPase activity requires 1 Mg2+ ion per subunit. Nuclease activity probably requires 2 Mg2+ ions per subunit.
Features
Showing features for active site, binding site.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Active site | 155 | For ATPase activity | ||||
Sequence: E | ||||||
Binding site | 286 | Mg2+ 1 (UniProtKB | ChEBI); catalytic; for nuclease activity | ||||
Sequence: D | ||||||
Binding site | 286 | Mg2+ 2 (UniProtKB | ChEBI); catalytic; for nuclease activity | ||||
Sequence: D | ||||||
Binding site | 342 | Mg2+ 2 (UniProtKB | ChEBI); catalytic; for nuclease activity | ||||
Sequence: D | ||||||
Binding site | 418 | Mg2+ 1 (UniProtKB | ChEBI); catalytic; for nuclease activity | ||||
Sequence: D |
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | viral terminase, large subunit | |
Molecular Function | ATP binding | |
Molecular Function | ATP hydrolysis activity | |
Molecular Function | endonuclease activity | |
Molecular Function | metal ion binding | |
Biological Process | chromosome organization | |
Biological Process | viral DNA genome packaging |
Keywords
- Molecular function
- Biological process
- Ligand
Names & Taxonomy
Protein names
- Recommended nameTerminase, large subunit
- Alternative names
Including 2 domains:
- Recommended nameATPase
- EC number
- Recommended nameEndonuclease
- EC number
Gene names
Organism names
- Organism
- Taxonomic lineageViruses > Duplodnaviria > Heunggongvirae > Uroviricota > Caudoviricetes > Demerecviridae > Markadamsvirinae > Tequintavirus > Tequintavirus chee24
Accessions
- Primary accessionA0A2K8HV90
Proteomes
Subcellular Location
UniProt Annotation
GO Annotation
Interaction
Subunit
Interacts with the terminase small subunit; the active complex is probably heterooligomeric. Interacts with the portal protein.
Family & Domains
Features
Showing features for motif, domain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Motif | 62-68 | Walker A motif | ||||
Sequence: SRRVGKS | ||||||
Motif | 150-155 | Walker B motif | ||||
Sequence: FIIFDE | ||||||
Domain | 284-431 | Terminase large subunit gp17-like C-terminal | ||||
Sequence: GIDVGYRDPTAVLTIKYHYDTDTYYVLEEYQQAEKTTAQHAAYIQHCIDRYKVDRIFVDSAAAQFRQDLAYEHEIASAPAKKSVLDGLACLQALFQQGKIIVDASCSSLIHALQNYKWDFQEGEEKLSREKPRHDANSHLCDALRYGI |
Domain
The N-terminus contains an ATPase domain. The C-terminus contains an endonuclease domain.
Sequence similarities
Belongs to the Tequatrovirus large terminase family.
Family and domain databases
Sequence
- Sequence statusComplete
- Length438
- Mass (Da)49,717
- Last updated2018-04-25 v1
- Checksum2BF5B121DEC69102