MCEL_VAR67
ID MCEL_VAR67 Reviewed; 844 AA.
AC P0DSX5; P33057; Q9QNI8;
DT 16-OCT-2019, integrated into UniProtKB/Swiss-Prot.
DT 16-OCT-2019, sequence version 1.
DT 03-AUG-2022, entry version 10.
DE RecName: Full=mRNA-capping enzyme catalytic subunit;
DE AltName: Full=Virus termination factor large subunit;
DE Short=VTF large subunit;
DE AltName: Full=mRNA-capping enzyme 97 kDa subunit;
DE AltName: Full=mRNA-capping enzyme D1 subunit;
DE AltName: Full=mRNA-capping enzyme large subunit;
DE Includes:
DE RecName: Full=Polynucleotide 5'-triphosphatase;
DE EC=3.1.3.33;
DE AltName: Full=mRNA 5'-triphosphatase;
DE Short=TPase;
DE Includes:
DE RecName: Full=mRNA guanylyltransferase;
DE EC=2.7.7.50;
DE AltName: Full=GTP--RNA guanylyltransferase;
DE Short=GTase;
DE Includes:
DE RecName: Full=mRNA (guanine-N(7))-methyltransferase;
DE EC=2.1.1.56;
DE AltName: Full=mRNA cap methyltransferase;
GN ORFNames=D1R, F1R;
OS Variola virus (isolate Human/India/Ind3/1967) (VARV) (Smallpox virus).
OC Viruses; Varidnaviria; Bamfordvirae; Nucleocytoviricota; Pokkesviricetes;
OC Chitovirales; Poxviridae; Chordopoxvirinae; Orthopoxvirus.
OX NCBI_TaxID=587200;
OH NCBI_TaxID=9606; Homo sapiens (Human).
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX PubMed=8383392; DOI=10.1016/0168-1702(93)90110-9;
RA Shchelkunov S.N., Blinov V.M., Totmenin A.V., Marennikova S.S.,
RA Kolykhalov A.A., Frolov I.V., Chizhikov V.E., Gytorov V.V., Gashikov P.V.,
RA Belanov E.F., Belavin P.A., Resenchuk S.M., Andzhaparidze O.G.,
RA Sandakhchiev L.S.;
RT "Nucleotide sequence analysis of variola virus HindIII M, L, I genome
RT fragments.";
RL Virus Res. 27:25-35(1993).
RN [2]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RX PubMed=8384129; DOI=10.1016/0014-5793(93)80041-r;
RA Shchelkunov S.N., Blinov V.M., Sandakhchiev L.S.;
RT "Genes of variola and vaccinia viruses necessary to overcome the host
RT protective mechanisms.";
RL FEBS Lett. 319:80-83(1993).
CC -!- FUNCTION: Catalytic subunit of the mRNA capping enzyme which catalyzes
CC three enzymatic reactions: the 5' triphosphate end of the pre-mRNA is
CC hydrolyzed to a diphosphate by RNA 5' triphosphatase; the diphosphate
CC RNA end is capped with GMP by RNA guanylyltransferase and the GpppN cap
CC is methylated by RNA (guanine-N7) methyltransferase. Heterodimeric mRNA
CC capping enzyme catalyzes the linkage of a N7-methyl-guanosine moiety to
CC the first transcribed nucleotide (cap 0 structure), whereas the
CC polymerase associated VP39 is responsible for a second methylation at
CC the 2'-O position of the ribose (cap 1 structure) (By similarity).
CC {ECO:0000250}.
CC -!- FUNCTION: The heterodimeric enzyme is also involved in early viral gene
CC transcription termination and intermediate viral gene transcription
CC initiation. Early gene transcription termination requires the
CC termination factor VTF, the DNA-dependent ATPase NPH-I and the Rap94
CC subunit of the viral RNA polymerase, as well as the presence of a
CC specific termination motif. Binds, together with RAP94, to the
CC termination motif 5'-UUUUUNU-3' in the nascent early mRNA (By
CC similarity). {ECO:0000250}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=a 5'-end triphospho-(purine-ribonucleoside) in mRNA + H2O = a
CC 5'-end diphospho-(purine-ribonucleoside) in mRNA + H(+) + phosphate;
CC Xref=Rhea:RHEA:11008, Rhea:RHEA-COMP:13929, Rhea:RHEA-COMP:13942,
CC ChEBI:CHEBI:15377, ChEBI:CHEBI:15378, ChEBI:CHEBI:43474,
CC ChEBI:CHEBI:138276, ChEBI:CHEBI:138288; EC=3.1.3.33;
CC -!- CATALYTIC ACTIVITY:
CC Reaction=a 5'-end diphospho-ribonucleoside in mRNA + GTP + H(+) = a 5'-
CC end (5'-triphosphoguanosine)-(ribonucleoside) in mRNA + diphosphate;
CC Xref=Rhea:RHEA:67012, Rhea:RHEA-COMP:17165, Rhea:RHEA-COMP:17166,
CC ChEBI:CHEBI:15378, ChEBI:CHEBI:33019, ChEBI:CHEBI:37565,
CC ChEBI:CHEBI:167616, ChEBI:CHEBI:167617; EC=2.7.7.50;
CC -!- CATALYTIC ACTIVITY:
CC Reaction=a 5'-end (5'-triphosphoguanosine)-(ribonucleoside) in mRNA +
CC S-adenosyl-L-methionine = a 5'-end (N(7)-methyl 5'-
CC triphosphoguanosine)-ribonucleoside in mRNA + S-adenosyl-L-
CC homocysteine; Xref=Rhea:RHEA:67008, Rhea:RHEA-COMP:17166, Rhea:RHEA-
CC COMP:17167, ChEBI:CHEBI:57856, ChEBI:CHEBI:59789, ChEBI:CHEBI:156461,
CC ChEBI:CHEBI:167617; EC=2.1.1.56; Evidence={ECO:0000255|PROSITE-
CC ProRule:PRU00895};
CC -!- COFACTOR:
CC Name=Mg(2+); Xref=ChEBI:CHEBI:18420;
CC Evidence={ECO:0000250|UniProtKB:P04298};
CC -!- SUBUNIT: Heterodimer of a catalytic and a regulatory subunit. Intrinsic
CC methyltransferase activity of the catalytic subunit is weak and needs
CC to be stimulated 30- to 50-fold by the regulatory subunit, which is
CC itself catalytically inert (By similarity). {ECO:0000250}.
CC -!- SUBCELLULAR LOCATION: Virion {ECO:0000305}. Note=All the enzymes and
CC other proteins required to synthesize early mRNAs are packaged within
CC the virion core along with the DNA genome.
CC -!- DOMAIN: The N-terminus contains the triphosphatase and
CC guanylyltransferase domains, whereas the C-terminus contains the
CC methyltransferase domain. The N-terminus is involved in binding to the
CC termination motif 5'-UUUUUNU-3' in the nascent mRNA (By similarity).
CC {ECO:0000250}.
CC -!- SIMILARITY: In the N-terminal section; belongs to the dsDNA virus mRNA
CC guanylyltransferase family. {ECO:0000305}.
CC -!- SIMILARITY: In the C-terminal section; belongs to the class I-like SAM-
CC binding methyltransferase superfamily. mRNA cap 0 methyltransferase
CC family. {ECO:0000255|PROSITE-ProRule:PRU00895}.
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DR EMBL; X67119; CAA47590.1; -; Genomic_DNA.
DR EMBL; X69198; CAA49032.1; -; Genomic_DNA.
DR PIR; G36846; G36846.
DR RefSeq; NP_042135.1; NC_001611.1.
DR SMR; P0DSX5; -.
DR GeneID; 1486417; -.
DR KEGG; vg:1486417; -.
DR Proteomes; UP000002060; Genome.
DR GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR GO; GO:0004482; F:mRNA (guanine-N7-)-methyltransferase activity; IEA:UniProtKB-EC.
DR GO; GO:0004484; F:mRNA guanylyltransferase activity; IEA:UniProtKB-EC.
DR GO; GO:0004651; F:polynucleotide 5'-phosphatase activity; IEA:UniProtKB-EC.
DR GO; GO:0003723; F:RNA binding; IEA:UniProtKB-KW.
DR Gene3D; 3.40.50.150; -; 1.
DR InterPro; IPR019602; mRNA_cap_ATPase/GuylTrfase_vir.
DR InterPro; IPR004971; mRNA_G-N7_MeTrfase_dom.
DR InterPro; IPR039753; RG7MT1.
DR InterPro; IPR029063; SAM-dependent_MTases_sf.
DR PANTHER; PTHR12189; PTHR12189; 1.
DR Pfam; PF10640; Pox_ATPase-GT; 1.
DR Pfam; PF03291; Pox_MCEL; 1.
DR SUPFAM; SSF53335; SSF53335; 1.
DR PROSITE; PS51562; RNA_CAP0_MT; 1.
PE 3: Inferred from homology;
KW Hydrolase; Magnesium; Metal-binding; Methyltransferase; mRNA capping;
KW mRNA processing; Multifunctional enzyme; Nucleotidyltransferase;
KW Reference proteome; RNA-binding; S-adenosyl-L-methionine; Transferase;
KW Virion.
FT CHAIN 1..844
FT /note="mRNA-capping enzyme catalytic subunit"
FT /id="PRO_0000210125"
FT DOMAIN 516..844
FT /note="mRNA cap 0 methyltransferase"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00895"
FT REGION 1..539
FT /note="Triphosphatase-guanylyltransferase"
FT /evidence="ECO:0000250"
FT ACT_SITE 260
FT /note="N6-GMP-lysine intermediate"
FT /evidence="ECO:0000250"
FT BINDING 37
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_note="catalytic; for RNA triphosphatase activity"
FT /evidence="ECO:0000250|UniProtKB:P04298"
FT BINDING 39
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_note="catalytic; for RNA triphosphatase activity"
FT /evidence="ECO:0000250|UniProtKB:P04298"
FT BINDING 192
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_note="catalytic; for RNA triphosphatase activity"
FT /evidence="ECO:0000250|UniProtKB:P04298"
FT BINDING 194
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_note="catalytic; for RNA triphosphatase activity"
FT /evidence="ECO:0000250|UniProtKB:P04298"
FT BINDING 549..550
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00895"
FT BINDING 569..570
FT /ligand="mRNA"
FT /ligand_id="ChEBI:CHEBI:33699"
FT /ligand_part="mRNA cap"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00895"
FT BINDING 573
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00895"
FT BINDING 598
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00895"
FT BINDING 620
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00895"
FT BINDING 678..680
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00895"
FT SITE 77
FT /note="Essential for RNA triphosphatase activity"
FT /evidence="ECO:0000250"
FT SITE 107
FT /note="Essential for RNA triphosphatase activity"
FT /evidence="ECO:0000250"
FT SITE 126
FT /note="Essential for RNA triphosphatase activity"
FT /evidence="ECO:0000250"
FT SITE 159
FT /note="Essential for RNA triphosphatase activity"
FT /evidence="ECO:0000250"
FT SITE 161
FT /note="Essential for RNA triphosphatase activity"
FT /evidence="ECO:0000250"
FT SITE 607
FT /note="mRNA cap binding"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00895"
FT SITE 632
FT /note="mRNA cap binding"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00895"
FT SITE 682
FT /note="mRNA cap binding"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00895"
FT SITE 763
FT /note="mRNA cap binding"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00895"
FT SITE 836
FT /note="mRNA cap binding"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00895"
SQ SEQUENCE 844 AA; 96729 MW; CAA2474D798115D1 CRC64;
MDANVVSSST IATYIDALAK NASELEQGST AYEINNELEL VFIKPPLITL TNVVNISTIQ
ESFIRFTVTN KEGVKIRTKI PLSKVHGLDV KNVQLVDAID NIVWEKKSLV TENRLHKACL
LRLSTEERHI FLDYKKYGSS IRLELVNLIQ AKTKNFTIDF KLKYFLGSGA QSKSSLLHAI
NHPKSRPNTS LEIEFTPRDN ETVPYDELIK ELTTFSRHIF MASPENVILS PPINAPIKTF
MLPKQDIVGM DLENLYAVTK TDGIPITIRV TSKGLYCYFT HLGYIIRYPV KRIIDSEVVV
FGEAVKDKNW TVYLIKLIEP VNAISDRLEE SKYVESKLVD ICDRIVFKSK KYEGPFTTTS
EVVDMLSTYL PKQPEGVILF YSKGPKSNID FKIKKENTID QTVNVVFRYM SSEPIIFGES
SIFIEYKKFT NDKGFPKEYG SGKIVLYNGV NYLNNIYCLE YINTHNEVGI KSVVVPIKFI
AEFLVNGEIL KPRIDKTMKY INSEDYYGNQ HNVIVEHLRD QSIKIGDVFN EDKLSDVGHQ
YANNDKFRLN PEVSYFTNKR TRGPLGILSN YVKTLLISMY CSKTFLDDSN KRKVLAIDFE
NGADLEKYFY GEIALLVATD PDADAIARGN ERYNKLNSGI KTKYYKFDYI QETIRSNTFV
SSVREVFYFG KFNIIDWQFA IHYSFHPRHY ATIMNNLSEL TASGGKVLIT TMDGDKLSKL
TDKKTFIIHK NLPSSENYMS VEKIADDRIV VYNPSTMSTP MTEYIIKKND IVRVFNEYGF
VLVDNVDFAT IIERSKKFIN GASTMEDRPS TRNFFELNRG AIKCEGLDVE DLLSYYVVYV
FSKR
