HAMAP rule MF_04146

General rule information [?]

Accession	MF_04146
Dates	7-FEB-2020 (Created) 19-NOV-2022 (Last updated, Version 7)

Name

TERL_T4

Scope

Viruses

Templates

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>

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 [?]

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;
	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 /ligand="ATP" /ligand_id="ChEBI:CHEBI:30616 Q 2

BINDING (Optional) 143 143 /ligand="ATP" /ligand_id="ChEBI:CHEBI:30616 Q 2

BINDING (Optional) 202 202 /ligand="ATP" /ligand_id="ChEBI:CHEBI:30616 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>

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 (Optional) 161 167 Walker A motif [PS]-R-[RQ]-[LV]-G-K-[ST]

end case

case <OC:Tequintavirus>

From: TERL_BPT5 (Q6QGD2)

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 (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

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