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Annotation rule MF_04146
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General rule information [?]

Accession MF_04146
Dates 7-FEB-2020 (Created)
7-APR-2020 (Last updated, Version 4)
Name TERL_T4
Scope
Viruses
Templates P17312 (TERL_BPT4); Q6QGD2 (TERL_BPT5): [Recover all]

Propagated annotation [?]


Identifier, protein and gene names [?]

Identifier
TERL
Protein name
RecName: Full=Terminase, large subunit;
AltName: Full=DNA-packaging protein;
Includes:
RecName: Full=ATPase;
EC 3.6.4.-;
Includes:
RecName: Full=Endonuclease;
EC 3.1.21.-;

Comments [?]

case <OC:Tequatrovirus>
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 full (headful packaging). Once the capsid is packaged with the DNA, the terminase complex is substituted by the tail.
Subunit Interacts with the terminase small subunit; the active complex is composed of a pentamer of terminase large subunits and a dodecamer of terminase small subunits. Interacts with the portal protein.
Activity regulation Stimulated up to 50 to 100-fold by the terminase small subunit.
else
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.
Subunit Interacts with the terminase small subunit; the active complex is probably heterooligomeric. Interacts with the portal protein.
end case
case <FTGroup:1> or <FTGroup:2>
Cofactor Mg(2+)
Note: ATPase activity requires 1 Mg(2+) ion per subunit. Nuclease activity probably requires 2 Mg(2+) ions per subunit.
end case
Domain The N-terminus contains an ATPase domain. The C-terminus contains an endonuclease domain.
Similarity Belongs to the Tequatrovirus large terminase family.

Keywords [?]

case <FTGroup:1> or <FTGroup:2>
end case

Gene Ontology [?]

GO:0098009; Cellular component: viral terminase, large subunit.
GO:0004519; Molecular function: endonuclease activity.
GO:0046872; Molecular function: metal ion binding.
GO:0004518; Molecular function: nuclease activity.
GO:0006323; Biological process: DNA packaging.
GO:0019073; Biological process: viral DNA genome packaging.

Cross-references [?]

Pfam PF03237; Terminase_6; 1;
PF17289; Terminase_6C; 1;

Features [?]

case <OC:Tequatrovirus>
From: TERL_BPT4 (P17312)
Key     From     To       Description   Tag   Condition   FTGroup
REGION     30     94       ssDNA-binding        
REGION     131     301       ATPase activity        
REGION     328     352       Binding to the portal protein        
REGION     360     559       Nuclease activity        
end case
BINDING (Optional)     138     138       ATP; via carbonyl oxygen     Q   2
BINDING (Optional)     143     143       ATP     Q   2
BINDING (Optional)     202     202       ATP     R   2
MOTIF (Optional)     251     256       Walker B motif     [FILMV]-[ILV]-[FIY]-[IFLV]-D-E  
MOTIF (Optional)     285     287       ATPase coupling     T-[ST]-T  
SITE (Optional)     409     409       Modulates nuclease activity     D  
ACT_SITE     256     256       For ATPase activity     E  
case not <OC:Tequintavirus>
METAL     401     401       Magnesium 1; catalytic; for nuclease activity     D   1
METAL     401     401       Magnesium 2; catalytic; for nuclease activity     D   1
METAL     458     458       Magnesium 2; catalytic; for nuclease activity     [DE]   1
METAL     542     542       Magnesium 1; catalytic; for nuclease activity     D   1
MOTIF (Optional)     161     167       Walker A motif     [PS]-R-[RQ]-[LV]-G-K-[ST]  
end case
case <OC:Tequintavirus>
From: TERL_BPT5 (Q6QGD2)
METAL     286     286       Magnesium 1; catalytic; for nuclease activity     D   2
METAL     286     286       Magnesium 2; catalytic; for nuclease activity     D   2
METAL     342     342       Magnesium 2; catalytic; for nuclease activity     D   2
METAL     418     418       Magnesium 1; catalytic; for nuclease activity     D   2
MOTIF (Optional)     62     68       Walker A motif     [PS]-R-[RQ]-[LV]-G-K-[ST]  
end case

Additional information [?]

Size range 400-650 amino acids
Related rules None
Fusion None