ID   MCES_VACCC              Reviewed;         287 AA.
AC   P20980;
DT   01-FEB-1991, integrated into UniProtKB/Swiss-Prot.
DT   01-FEB-1991, sequence version 1.
DT   29-SEP-2021, entry version 82.
DE   RecName: Full=mRNA-capping enzyme regulatory subunit;
DE   AltName: Full=Virus termination factor small subunit;
DE            Short=VTF small subunit;
DE   AltName: Full=mRNA-capping enzyme 33 kDa subunit;
DE   AltName: Full=mRNA-capping enzyme D12 subunit;
DE   AltName: Full=mRNA-capping enzyme small subunit;
GN   ORFNames=D12L;
OS   Vaccinia virus (strain Copenhagen) (VACV).
OC   Viruses; Varidnaviria; Bamfordvirae; Nucleocytoviricota; Pokkesviricetes;
OC   Chitovirales; Poxviridae; Chordopoxvirinae; Orthopoxvirus; Vaccinia virus.
OX   NCBI_TaxID=10249;
OH   NCBI_TaxID=9606; Homo sapiens (Human).
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RX   PubMed=2219722; DOI=10.1016/0042-6822(90)90294-2;
RA   Goebel S.J., Johnson G.P., Perkus M.E., Davis S.W., Winslow J.P.,
RA   Paoletti E.;
RT   "The complete DNA sequence of vaccinia virus.";
RL   Virology 179:247-266(1990).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RA   Goebel S.J., Johnson G.P., Perkus M.E., Davis S.W., Winslow J.P.,
RA   Paoletti E.;
RT   "Appendix to 'The complete DNA sequence of vaccinia virus'.";
RL   Virology 179:517-563(1990).
CC   -!- FUNCTION: Regulatory subunit of the mRNA cap enzyme which stabilizes
CC       the catalytic subunit and enhances its methyltransferase activity
CC       through an allosteric mechanism. Heterodimeric mRNA capping enzyme
CC       catalyzes the linkage of a N7-methyl-guanosine moiety to the first
CC       transcribed nucleotide (cap 0 structure), whereas the polymerase
CC       associated VP39 is responsible for a second methylation at the 2'-O
CC       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   -!- 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   -!- SIMILARITY: Belongs to the chordopoxvirinae mRNA-capping enzyme
CC       regulatory subunit family. {ECO:0000305}.
CC   ---------------------------------------------------------------------------
CC   Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms
CC   Distributed under the Creative Commons Attribution (CC BY 4.0) License
CC   ---------------------------------------------------------------------------
DR   EMBL; M35027; AAA48113.1; -; Genomic_DNA.
DR   PIR; B42516; B42516.
DR   SMR; P20980; -.
DR   Proteomes; UP000008269; Genome.
DR   GO; GO:0004482; F:mRNA (guanine-N7-)-methyltransferase activity; IEA:InterPro.
DR   GO; GO:0006353; P:DNA-templated transcription, termination; IEA:UniProtKB-KW.
DR   Gene3D; 3.40.50.11680; -; 1.
DR   InterPro; IPR005009; Poxvirus_mRNA-cap_ssu.
DR   InterPro; IPR043096; Poxvirus_mRNA-cap_ssu_sf.
DR   Pfam; PF03341; Pox_mRNA-cap; 1.
PE   3: Inferred from homology;
KW   mRNA capping; mRNA processing; Reference proteome; Transcription;
KW   Transcription regulation; Transcription termination; Virion.
FT   CHAIN           1..287
FT                   /note="mRNA-capping enzyme regulatory subunit"
FT                   /id="PRO_0000210136"
SQ   SEQUENCE   287 AA;  33353 MW;  B09CE30A7BDACA56 CRC64;
     MDEIVKNIRE GTHVLLPFYE TLPELNLSLG KSPLPSLEYG ANYFLQISRV NDLNRMPTDM
     LKLFTHDIML PESDLDKVYE ILKINSVKYY GRSTKADAVV ADLSARNKLF KRERDAIKSN
     NHLTENNLYI SDYKMLTFDV FRPLFDFVNE KYCIIKLPTL FGRGVIDTMR IYCSLFKNVR
     LLKCVSDSWL KDSAIMVASD VCKKNLDLFM SHVKSVTKSS SWKDVNSVQF SILNDPVDTE
     FINKFLEFSN RVYEALYYVH SLLYSSMTSD SKSIENKHQR RLVKLLL