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HAMAP rule MF_04146

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General rule information [?]

Accession MF_04146
Dates 7-FEB-2020 (Created)
19-NOV-2022 (Last updated, Version 7)
Name TERL_T4
Scope(s) Viruses
Template(s) P17312 (TERL_BPT4); Q6QGD2 (TERL_BPT5); [ Recover all ]
Triggered by HAMAP; MF_04146 (Get profile general information and statistics)

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>
FUNCTIONThe 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.
SUBUNITInteracts 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 REGULATIONStimulated up to 50 to 100-fold by the terminase small subunit.
else
FUNCTIONThe 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.
SUBUNITInteracts 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 Name=Mg(2+); Xref=ChEBI:CHEBI:18420; Note=ATPase activity requires 1 Mg(2+) ion per subunit. Nuclease activity probably requires 2 Mg(2+) ions per subunit.;
end case
DOMAINThe N-terminus contains an ATPase domain. The C-terminus contains an endonuclease domain.
SIMILARITYBelongs to the Tequatrovirus large terminase family.

Keywords [?]

ATP-binding
Endonuclease
Hydrolase
case <FTGroup:1> or <FTGroup:2>
Magnesium
Metal-binding
end case
Nuclease
Nucleotide-binding
Viral genome packaging
Viral release from host cell

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:0051276; Biological process:chromosome organization
GO:0019073; Biological process:viral DNA genome packaging

Cross-references [?]

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

Features [?]

From: TERL_BPT4 (P17312)
Key From To Description Tag Condition FTGroup
case <OC:Tequatrovirus>
REGION 30 94 /note="ssDNA-binding"
REGION 131 301 /note="ATPase activity"
REGION 328 352 /note="Binding to the portal protein"
REGION 360 559 /note="Nuclease activity"
end case
BINDING 138 138 /ligand="ATP"
/ligand_id="ChEBI:CHEBI:30616"		 Q 2
BINDING 143 143 /ligand="ATP"
/ligand_id="ChEBI:CHEBI:30616"		 Q 2
BINDING 202 202 /ligand="ATP"
/ligand_id="ChEBI:CHEBI:30616"		 R 2
MOTIF 251 256 /note="Walker B motif" [FILMV]-[ILV]-[FIY]-[IFLV]-D-E
MOTIF 285 287 /note="ATPase coupling" T-[ST]-T
SITE 409 409 /note="Modulates nuclease activity" D
ACT_SITE 256 256 /note="For ATPase activity" E
case not <OC:Tequintavirus>
BINDING 401 401 /ligand="Mg(2+)"
/ligand_id="ChEBI:CHEBI:18420"
/ligand_label="1"
/ligand_note="catalytic; for nuclease activity"		 D 1
BINDING 401 401 /ligand="Mg(2+)"
/ligand_id="ChEBI:CHEBI:18420"
/ligand_label="2"
/ligand_note="catalytic; for nuclease activity"		 D 1
BINDING 458 458 /ligand="Mg(2+)"
/ligand_id="ChEBI:CHEBI:18420"
/ligand_label="2"
/ligand_note="catalytic; for nuclease activity"		 [DE] 1
BINDING 542 542 /ligand="Mg(2+)"
/ligand_id="ChEBI:CHEBI:18420"
/ligand_label="1"
/ligand_note="catalytic; for nuclease activity"		 D 1
MOTIF 161 167 /note="Walker A motif" [PS]-R-[RQ]-[LV]-G-K-[ST]
end case
From: TERL_BPT5 (Q6QGD2)
Key From To Description Tag Condition FTGroup
case <OC:Tequintavirus>
BINDING 286 286 /ligand="Mg(2+)"
/ligand_id="ChEBI:CHEBI:18420"
/ligand_label="1"
/ligand_note="catalytic; for nuclease activity"		 D 2
BINDING 286 286 /ligand="Mg(2+)"
/ligand_id="ChEBI:CHEBI:18420"
/ligand_label="2"
/ligand_note="catalytic; for nuclease activity"		 D 2
BINDING 342 342 /ligand="Mg(2+)"
/ligand_id="ChEBI:CHEBI:18420"
/ligand_label="2"
/ligand_note="catalytic; for nuclease activity"		 D 2
BINDING 418 418 /ligand="Mg(2+)"
/ligand_id="ChEBI:CHEBI:18420"
/ligand_label="1"
/ligand_note="catalytic; for nuclease activity"		 D 2
MOTIF 62 68 /note="Walker A motif" [PS]-R-[RQ]-[LV]-G-K-[ST]
end case

Additional information [?]

Size range 400-650 amino acids
Related rules None
Fusion Nter: None Cter: None



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