UniProt functional annotation for P04298



	UniProt functional annotation for P04298

UniProt code: P04298.

Organism: Vaccinia virus (strain Western Reserve) (VACV) (Vaccinia virus (strain WR)).

Taxonomy: Viruses; Varidnaviria; Bamfordvirae; Nucleocytoviricota; Pokkesviricetes; Chitovirales; Poxviridae; Chordopoxvirinae; Orthopoxvirus; Vaccinia virus.

Function: Catalytic subunit of the mRNA capping enzyme which catalyzes three enzymatic reactions: the 5' triphosphate end of the pre-mRNA is hydrolyzed to a diphosphate by RNA 5' triphosphatase; the diphosphate RNA end is capped with GMP by RNA guanylyltransferase and the GpppN cap is methylated by RNA (guanine-N7) methyltransferase. Heterodimeric mRNA capping enzyme catalyzes the linkage of a N7-methyl-guanosine moiety to the first transcribed nucleotide (cap 0 structure), whereas the polymerase associated VP39 is responsible for a second methylation at the 2'-O position of the ribose (cap 1 structure).

Function: The heterodimeric enzyme is also involved in early viral gene transcription termination and intermediate viral gene transcription initiation. Early gene transcription termination requires the termination factor VTF, the DNA-dependent ATPase NPH-I and the Rap94 subunit of the viral RNA polymerase, as well as the presence of a specific termination motif. Binds, together with RAP94, to the termination motif 5'-UUUUUNU-3' in the nascent early mRNA.

Catalytic activity: Reaction=a 5'-end triphospho-(purine-ribonucleoside) in mRNA + H2O = a 5'-end diphospho-(purine-ribonucleoside) in mRNA + H(+) + phosphate; Xref=Rhea:RHEA:11008, Rhea:RHEA-COMP:13929, Rhea:RHEA-COMP:13942, ChEBI:CHEBI:15377, ChEBI:CHEBI:15378, ChEBI:CHEBI:43474, ChEBI:CHEBI:138276, ChEBI:CHEBI:138288; EC=3.1.3.33;

Catalytic activity: Reaction=a 5'-end diphospho-ribonucleoside in mRNA + GTP + H(+) = a 5'- end (5'-triphosphoguanosine)-(ribonucleoside) in mRNA + diphosphate; Xref=Rhea:RHEA:67012, Rhea:RHEA-COMP:17165, Rhea:RHEA-COMP:17166, ChEBI:CHEBI:15378, ChEBI:CHEBI:33019, ChEBI:CHEBI:37565, ChEBI:CHEBI:167616, ChEBI:CHEBI:167617; EC=2.7.7.50;

Catalytic activity: Reaction=a 5'-end (5'-triphosphoguanosine)-(ribonucleoside) in mRNA + S-adenosyl-L-methionine = a 5'-end (N(7)-methyl 5'- triphosphoguanosine)-ribonucleoside in mRNA + S-adenosyl-L- homocysteine; Xref=Rhea:RHEA:67008, Rhea:RHEA-COMP:17166, Rhea:RHEA- COMP:17167, ChEBI:CHEBI:57856, ChEBI:CHEBI:59789, ChEBI:CHEBI:156461, ChEBI:CHEBI:167617; EC=2.1.1.56; Evidence={ECO:0000255|PROSITE- ProRule:PRU00895};

Cofactor: Name=Mg(2+); Xref=ChEBI:CHEBI:18420; Evidence={ECO:0000305|PubMed:2164022, ECO:0000305|PubMed:24607143};

Biophysicochemical properties: Kinetic parameters: KM=23 uM for GpppA {ECO:0000269|PubMed:18256245}; Note=A-570 and A-763 mutants have 3-fold and 10-fold higher Km values for GpppA.;

Subunit: Heterodimer of a catalytic and a regulatory subunit. Intrinsic methyltransferase activity of the catalytic subunit is weak and needs to be stimulated 30- to 50-fold by the regulatory subunit, which is itself catalytically inert. {ECO:0000269|PubMed:17989694}.

Subcellular location: Virion {ECO:0000305}. Note=All the enzymes and other proteins required to synthesize early mRNAs are packaged within the virion core along with the DNA genome.

Domain: The N-terminus contains the triphosphatase and guanylyltransferase domains, whereas the C-terminus contains the methyltransferase domain. The N-terminus is involved in binding to the termination motif 5'-UUUUUNU-3' in the nascent mRNA. {ECO:0000269|PubMed:7929111}.

Similarity: In the N-terminal section; belongs to the dsDNA virus mRNA guanylyltransferase family. {ECO:0000305}.

Similarity: In the C-terminal section; belongs to the class I-like SAM- binding methyltransferase superfamily. mRNA cap 0 methyltransferase family. {ECO:0000255|PROSITE-ProRule:PRU00895}.

Annotations taken from UniProtKB at the EBI.


Organism:		Vaccinia virus (strain Western Reserve) (VACV) (Vaccinia virus (strain WR)).
Taxonomy:		Viruses; Varidnaviria; Bamfordvirae; Nucleocytoviricota; Pokkesviricetes; Chitovirales; Poxviridae; Chordopoxvirinae; Orthopoxvirus; Vaccinia virus.



Function:		Catalytic subunit of the mRNA capping enzyme which catalyzes three enzymatic reactions: the 5' triphosphate end of the pre-mRNA is hydrolyzed to a diphosphate by RNA 5' triphosphatase; the diphosphate RNA end is capped with GMP by RNA guanylyltransferase and the GpppN cap is methylated by RNA (guanine-N7) methyltransferase. Heterodimeric mRNA capping enzyme catalyzes the linkage of a N7-methyl-guanosine moiety to the first transcribed nucleotide (cap 0 structure), whereas the polymerase associated VP39 is responsible for a second methylation at the 2'-O position of the ribose (cap 1 structure).



Function:		The heterodimeric enzyme is also involved in early viral gene transcription termination and intermediate viral gene transcription initiation. Early gene transcription termination requires the termination factor VTF, the DNA-dependent ATPase NPH-I and the Rap94 subunit of the viral RNA polymerase, as well as the presence of a specific termination motif. Binds, together with RAP94, to the termination motif 5'-UUUUUNU-3' in the nascent early mRNA.


Catalytic activity:		Reaction=a 5'-end triphospho-(purine-ribonucleoside) in mRNA + H2O = a 5'-end diphospho-(purine-ribonucleoside) in mRNA + H(+) + phosphate; Xref=Rhea:RHEA:11008, Rhea:RHEA-COMP:13929, Rhea:RHEA-COMP:13942, ChEBI:CHEBI:15377, ChEBI:CHEBI:15378, ChEBI:CHEBI:43474, ChEBI:CHEBI:138276, ChEBI:CHEBI:138288; EC=3.1.3.33;
Catalytic activity:		Reaction=a 5'-end diphospho-ribonucleoside in mRNA + GTP + H(+) = a 5'- end (5'-triphosphoguanosine)-(ribonucleoside) in mRNA + diphosphate; Xref=Rhea:RHEA:67012, Rhea:RHEA-COMP:17165, Rhea:RHEA-COMP:17166, ChEBI:CHEBI:15378, ChEBI:CHEBI:33019, ChEBI:CHEBI:37565, ChEBI:CHEBI:167616, ChEBI:CHEBI:167617; EC=2.7.7.50;
Catalytic activity:		Reaction=a 5'-end (5'-triphosphoguanosine)-(ribonucleoside) in mRNA + S-adenosyl-L-methionine = a 5'-end (N(7)-methyl 5'- triphosphoguanosine)-ribonucleoside in mRNA + S-adenosyl-L- homocysteine; Xref=Rhea:RHEA:67008, Rhea:RHEA-COMP:17166, Rhea:RHEA- COMP:17167, ChEBI:CHEBI:57856, ChEBI:CHEBI:59789, ChEBI:CHEBI:156461, ChEBI:CHEBI:167617; EC=2.1.1.56; Evidence={ECO:0000255\|PROSITE- ProRule:PRU00895};
Cofactor:		Name=Mg(2+); Xref=ChEBI:CHEBI:18420; Evidence={ECO:0000305\|PubMed:2164022, ECO:0000305\|PubMed:24607143};
Biophysicochemical properties:		Kinetic parameters: KM=23 uM for GpppA {ECO:0000269\|PubMed:18256245}; Note=A-570 and A-763 mutants have 3-fold and 10-fold higher Km values for GpppA.;
Subunit:		Heterodimer of a catalytic and a regulatory subunit. Intrinsic methyltransferase activity of the catalytic subunit is weak and needs to be stimulated 30- to 50-fold by the regulatory subunit, which is itself catalytically inert. {ECO:0000269\|PubMed:17989694}.
Subcellular location:		Virion {ECO:0000305}. Note=All the enzymes and other proteins required to synthesize early mRNAs are packaged within the virion core along with the DNA genome.
Domain:		The N-terminus contains the triphosphatase and guanylyltransferase domains, whereas the C-terminus contains the methyltransferase domain. The N-terminus is involved in binding to the termination motif 5'-UUUUUNU-3' in the nascent mRNA. {ECO:0000269\|PubMed:7929111}.
Similarity:		In the N-terminal section; belongs to the dsDNA virus mRNA guanylyltransferase family. {ECO:0000305}.
Similarity:		In the C-terminal section; belongs to the class I-like SAM- binding methyltransferase superfamily. mRNA cap 0 methyltransferase family. {ECO:0000255\|PROSITE-ProRule:PRU00895}.