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Annotation rule MF_04154
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General rule information [?]

Accession MF_04154
Dates 8-FEB-2021 (Created)
31-MAR-2021 (Last updated, Version 4)
Name Helic_Prim_T7
Scope
Viruses
Template P03692 (HELIC_BPT7)

Propagated annotation [?]


Identifier, protein and gene names [?]

Identifier
HELIC
Protein name
RecName: Full=DNA helicase/primase;
EC 2.7.7.-;
EC 3.6.4.12;
case <OC:Teseptimavirus>
Protein name
AltName: Full=Gene product 4;
Short=Gp4;
Gene name
4
end case

Comments [?]

case <OC:Teseptimavirus>
Function ATP-dependent DNA helicase and primase essential for viral DNA replication and recombination. The helicase moves 5' -> 3' on the lagging strand template, unwinding the DNA duplex ahead of the leading strand polymerase at the replication fork and generating ssDNA for both leading and lagging strand synthesis. ATP or dTTP hydrolysis propels each helicase domain to translocate 2 nt per step sequentially along DNA. Mediates strand transfer when a joint molecule is available and participates in recombinational DNA repair through its role in strand exchange. Primase activity synthesizes short RNA primers at the sequence 5'-GTC-3' on the lagging strand that the polymerase elongates using dNTPs and providing the primase is still present.
else
Function ATP-dependent DNA helicase and primase essential for viral DNA replication and recombination. The helicase moves 5' -> 3' on the lagging strand template, unwinding the DNA duplex ahead of the leading strand polymerase at the replication fork and generating ssDNA for both leading and lagging strand synthesis. ATP or dTTP hydrolysis propels each helicase domain to translocate sequentially along DNA. Mediates strand transfer when a joint molecule is available and participates in recombinational DNA repair through its role in strand exchange. Primase activity synthesizes short RNA primers at the sequence 5'-GTC-3' on the lagging strand that the polymerase elongates using dNTPs and providing the primase is still present.
end case
Catalytic activity RHEA:13065: ATP + H2O = ADP + H(+) + phosphate
EC 3.6.4.12
Cofactor Mg(2+)
Note: Binds 2 Mg(2+), one of which is catalytic.
case <OC:Teseptimavirus>
Subunit Homohexamer. Assembles as a hexamer onto linear or circular ssDNA in the presence of ATP or dTTP. Interacts (via C-terminus) with the viral DNA polymerase that is bound to DNA; this interaction is essential to initiate leading-strand DNA synthesis. The priming complex consists of 2 DNA polymerases and 1 helicase-primase hexamer that assemble on the DNA template. Interacts with the single-stranded DNA-binding protein. Part of the replicase complex that includes the DNA polymerase, thioredoxin, the primase/helicase and the single-stranded DNA binding protein.
else
Subunit Homohexamer. Assembles as a hexamer onto linear or circular ssDNA in the presence of ATP or dTTP. Interacts (via C-terminus) with the viral DNA polymerase that is bound to DNA; this interaction is essential to initiate leading-strand DNA synthesis. The priming complex consists of 2 DNA polymerases and 1 helicase-primase hexamer that assemble on the DNA template. Interacts with the single-stranded DNA-binding protein. Part of the replicase complex that includes the DNA polymerase, the primase/helicase and the single-stranded DNA binding protein.
end case
case <FTGroup:1> and <FTGroup:2>
Domain The N-terminus zinc finger domain is essential for delivering the primed DNA template to the DNA polymerase. The central core domain contains the primase activity. The C-terminus region is responsible for the helicase activity and binds 1 Mg(2+)-dTTP.
else case <FTGroup:2> and not <FTGroup:1>
Domain The central core domain contains the primase activity. The C-terminus is responsible for the helicase activity.
end case
Similarity Belongs to the Teseptimavirus DNA helicase/primase family.

Keywords [?]

case <FTGroup:2>
end case

Gene Ontology [?]

GO:0003896; Molecular function: DNA primase activity.
case <FTGroup:1>
GO:0008270; Molecular function: zinc ion binding.
end case
GO:0005524; Molecular function: ATP binding.
GO:0003678; Molecular function: DNA helicase activity.
GO:0039693; Biological process: viral DNA genome replication.
GO:0016740; Molecular function: transferase activity.

Cross-references [?]

PROSITE PS50880; TOPRIM; 1;
PS51199; SF4_HELICASE; 1; trigger=PRU00596;
Pfam PF03796; DnaB_C; 1;
PF08273; Prim_Zn_Ribbon; 0-1;

Features [?]

From: HELIC_BPT7 (P03692)
Key     From     To       Description   Tag   Condition   FTGroup
ZN_FING     17     39       C4-like; zinc ribbon fold     C-x(2,4)-C-x(15,21)-C-x(2)-C  
NP_BIND     312     319       ATP     [AS]-G-[ST]-G-x-G-K-[ST]  
REGION     550     566       Binding to viral DNA polymerase        
METAL     17     17       Zinc     C   1
METAL     20     20       Zinc     C   1
METAL     36     36       Zinc     C   1
METAL     39     39       Zinc     C   1
METAL     157     157       Magnesium 1; catalytic     E   2
METAL     207     207       Magnesium 1; catalytic     D   2
METAL     237     237       Magnesium 2     D  
SITE     361     361       dTTP/dATP binding     R  
SITE     465     465       dTTP/dATP binding     H  
SITE     504     504       dTTP/dATP binding     R  
SITE     522     522       dTTP/dATP binding     R  
SITE     535     535       dTTP/dATP binding     Y  

Additional information [?]

Size range 460-650 amino acids
Related rules None
Fusion None