Q9JFA8 (MCEL_VACCT) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
mRNA-capping enzyme catalytic subunit

Alternative name(s):
Virus termination factor large subunit
Short name=VTF large subunit
mRNA-capping enzyme 97 kDa subunit
mRNA-capping enzyme D1 subunit
mRNA-capping enzyme large subunit

Including the following 3 domains:

1. Polynucleotide 5'-triphosphatase
   EC=3.1.3.33
   Alternative name(s):
   mRNA 5'-triphosphatase
   Short name=TPase
2. mRNA guanylyltransferase
   EC=2.7.7.50
   Alternative name(s):
   GTP--RNA guanylyltransferase
   Short name=GTase
3. mRNA (guanine-N(7)-)-methyltransferase
   EC=2.1.1.56
   Alternative name(s):
   mRNA cap methyltransferase

Gene names

ORF Names:

TD1R

Organism

Vaccinia virus (strain Tian Tan) (VACV)

Taxonomic identifier

10253 [NCBI]

Taxonomic lineage

Viruses › dsDNA viruses, no RNA stage › Poxviridae › Chordopoxvirinae › Orthopoxvirus › Vaccinia virus

Virus host

Homo sapiens (Human) [TaxID: 9606]

Protein attributes

Sequence length	844 AA.
Sequence status	Complete.
Protein existence	Inferred from homology

General annotation (Comments)

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) By similarity. 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 By similarity.
Catalytic activity	A 5'-phosphopolynucleotide + H2O = a polynucleotide + phosphate. GTP + (5')pp-Pur-mRNA = diphosphate + G(5')ppp-Pur-mRNA. S-adenosyl-L-methionine + G(5')pppR-RNA = S-adenosyl-L-homocysteine + m7G(5')pppR-RNA.
Subunit structure	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 By similarity.
Subcellular location	Virion Probable. 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 temination motif 5'-UUUUUNU-3' in the nascent mRNA By similarity.
Sequence similarities	Belongs to the viral GTase family.

Ontologies

Keywords
Biological process	mRNA capping mRNA processing
Cellular component	Virion
Ligand	GTP-binding Metal-binding Nucleotide-binding S-adenosyl-L-methionine
Molecular function	Hydrolase Methyltransferase Nucleotidyltransferase Transferase
Technical term	Multifunctional enzyme
Gene Ontology (GO)
Biological process	mRNA capping Inferred from electronic annotation. Source: UniProtKB-KW
Cellular component	virion Inferred from electronic annotation. Source: UniProtKB-SubCell
Molecular function	GTP binding Inferred from electronic annotation. Source: UniProtKB-KW mRNA (guanine-N7-)-methyltransferase activity Inferred from electronic annotation. Source: EC mRNA guanylyltransferase activity Inferred from electronic annotation. Source: EC metal ion binding Inferred from electronic annotation. Source: UniProtKB-KW polynucleotide 5'-phosphatase activity Inferred from electronic annotation. Source: EC
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Chain	1 – 844	844	mRNA-capping enzyme catalytic subunit		PRO_0000210123
Regions
	Region	1 – 539	539	Triphosphatase-guanylyltransferase By similarity
	Region	540 – 844	305	Methyltransferase By similarity
Sites
	Active site	260	1	N6-GMP-lysine intermediate By similarity
	Metal binding	37	1	Catalytic; for RNA triphosphatase activity Potential
	Metal binding	39	1	Catalytic; for RNA triphosphatase activity Potential
	Metal binding	192	1	Catalytic; for RNA triphosphatase activity Potential
	Metal binding	194	1	Catalytic; for RNA triphosphatase activity Potential
	Site	77	1	Essential for RNA triphosphatase activity By similarity
	Site	107	1	Essential for RNA triphosphatase activity By similarity
	Site	126	1	Essential for RNA triphosphatase activity By similarity
	Site	159	1	Essential for RNA triphosphatase activity By similarity
	Site	161	1	Essential for RNA triphosphatase activity By similarity

Sequences

	Sequence		Length	Mass (Da)
	Q9JFA8 [UniParc]. Last modified October 1, 2000. Version 1. Checksum: 54283DA9CC62FDE7	FASTA	844	96,717
	10 20 30 40 50 60 MDANVVSSST IATYIDALAK NASELEQRST AYEINNELEL VFIKPPLITL TNVVNISTIQ 70 80 90 100 110 120 ESFIRFTVTN KEGVKIRTKI PLSKVHGLDV KNVQLVDAID NIVWEKKSLV TENRLHKECL 130 140 150 160 170 180 LRLSTEERHI FLDYKKYGSS IRLELVNLIQ AKTKNFTIDF KLKYFLGSGA QSKSSLLHAI 190 200 210 220 230 240 NHPKSRPNTS LEIEFTPRDN EKVPYDELIK ELTTLSRHIF MASPENVILS PPINAPIKTF 250 260 270 280 290 300 MLPKQDIVGL DLENLYAVTK TDGIPITIRV TSNGLYCYFT HLGYIIRYPV KRIIDSEVVV 310 320 330 340 350 360 FGEAVKDKNW TVYLIKLIEP VNAINDRLEE SKYVESKLVD ICDRIVFKSK KYEGPFTTTS 370 380 390 400 410 420 EVVDMLSTYL PKQPEGVILF YSKGPKSNID FKIKKENTID QTANVVFRYM SSEPIIFGES 430 440 450 460 470 480 SIFVEYKKFS NDKGFPKEYG SGKIVLYNGV NYLNNIYCLE YINTHNEVGI KSVVVPIKFI 490 500 510 520 530 540 AEFLVNGEIL KPRIDKTMKY INSEDYYGNQ HNIIVEHLRD QSIKIGDIFN EDKLSDVGHQ 550 560 570 580 590 600 YANNDKFRLN PAVSYFTNKR TRGPLGILSN YVKTLLISMY CSKTFLDDSN KRKVLAIDFG 610 620 630 640 650 660 NGADLEKYFY GEIALLVATD PDADAIARGN ERYNKLNSGI KTKYYKFDYI QETIRSDTFV 670 680 690 700 710 720 SSVREVFYFG KFKIIDWQFA IHYSFHPRHY ATVMNNLSEL TASGGKVLIT TMDGDKLSKL 730 740 750 760 770 780 TDKKTFIIHK NLPSSENYMS VEKIADDRIV VYNPSTMSTP MTEYIIKKND IVRVFNEYGF 790 800 810 820 830 840 VLVDNVDFAT IIERSKKFIN GASTMEDRPS TRNFFELNRG AIKCEGLDVE DLLSYYVVYV FSKR

References

[1]	"Complete genomic sequence of vaccinia virus (Tian Tan strain)." Jin Q., Hou Y.D., Cheng N.H., Yao E.M., Cheng S.X., Yang X.K., Jing D.Y., Yu W.H., Yuan J.S., Ma X.J. Submitted (SEP-1998) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].

Cross-references

Sequence databases
EMBL GenBank DDBJ	AF095689 Genomic DNA. Translation: AAF33967.1.
3D structure databases
ProteinModelPortal	Q9JFA8.
SMR	Q9JFA8. Positions 545-844.
ModBase	Search...
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Family and domain databases
InterPro	IPR019602. mRNA_cap_ATPase/GuylTrfase_vir. IPR004971. Pox_MCEL. [Graphical view]
Pfam	PF10640. Pox_ATPase-GT. 1 hit. PF03291. Pox_MCEL. 1 hit. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

MCEL_VACCT

Accession

Primary (citable) accession number: Q9JFA8

Entry history

Integrated into UniProtKB/Swiss-Prot:	December 7, 2004
Last sequence update:	October 1, 2000
Last modified:	January 25, 2012
This is version 30 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Viral Protein Annotation Program