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Annotation rule MF_04148
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General rule information [?]

Accession MF_04148
Dates 18-FEB-2020 (Created)
7-APR-2020 (Last updated, Version 2)
Name TERL_BPP22
Scope
Viruses
Template P26745 (TERL_BPP22)

Propagated annotation [?]


Identifier, protein and gene names [?]

Identifier
TERL
Protein name
RecName: Full=Terminase, large subunit;
AltName: Full=DNA-packaging protein gp2;
Includes:
RecName: Full=Endonuclease;
EC 3.1.21.-;
Includes:
RecName: Full=ATPase;
EC 3.6.4.-;

Comments [?]

case <OC:Lederbergvirus>
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.
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. Once the capsid is packaged with the DNA, the terminase cleaves the viral genome concatemer and is substituted by the tail.
end case
case <FTGroup:1>
Cofactor Mg(2+)
Note: Nuclease activity probably requires 2 Mg(2+) ions per subunit
end case
Subunit Interacts with the terminase small subunit; the active complex is composed of a monomer of the terminase large subunit and a nonamer ring of terminase small subunits. Interacts with the portal protein; this interaction allows the packaging of viral DNA.
Domain The ATPase region is in the N-terminus, whereas the nuclease region is in the C-terminus.
Similarity Belongs to the Lederbergvirus large terminase family.

Keywords [?]

case <FTGroup:1>
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:Lederbergvirus>
From: TERL_BPP22 (P26745)
Key     From     To       Description   Tag   Condition   FTGroup
REGION     1     58       Interaction with the terminase small subunit        
REGION     1     286       ATPase activity        
REGION     312     482       Nuclease activity        
end case
MOTIF     60     67       Walker A motif     [ACT]-[AG]-N-[QR]-[CILV]-G-K-[ST]  
MOTIF     199     204       Walker B motif     [FGILVWY]-[FIV]-[WH]-[FILM]-D-E  
ACT_SITE     204     204       For ATPase activity     E  
METAL     321     321       Magnesium; catalytic; for nuclease activity     D   1
METAL     459     459       Magnesium; catalytic; for nuclease activity     D   1

Additional information [?]

Size range 400-530 amino acids
Related rules None
Fusion None