L_HRSV
ID L_HRSV Reviewed; 81 AA.
AC P20894;
DT 01-FEB-1991, integrated into UniProtKB/Swiss-Prot.
DT 01-FEB-1991, sequence version 1.
DT 29-SEP-2021, entry version 88.
DE RecName: Full=RNA-directed RNA polymerase L;
DE Short=Protein L;
DE AltName: Full=Large structural protein;
DE AltName: Full=Replicase;
DE AltName: Full=Transcriptase;
DE Includes:
DE RecName: Full=RNA-directed RNA polymerase;
DE EC=2.7.7.48 {ECO:0000250|UniProtKB:P28887};
DE Includes:
DE RecName: Full=GTP phosphohydrolase {ECO:0000250|UniProtKB:P28887};
DE EC=3.6.1.- {ECO:0000250|UniProtKB:P28887};
DE Includes:
DE RecName: Full=GDP polyribonucleotidyltransferase {ECO:0000305};
DE EC=2.7.7.88 {ECO:0000250|UniProtKB:P28887};
DE AltName: Full=PRNTase {ECO:0000305};
DE Includes:
DE RecName: Full=mRNA cap methyltransferase {ECO:0000305};
DE EC=2.1.1.375 {ECO:0000250|UniProtKB:P03523};
DE AltName: Full=mRNA (guanine-N(7)-)-methyltransferase {ECO:0000250|UniProtKB:P03523};
DE Short=G-N7-MTase {ECO:0000250|UniProtKB:P03523};
DE AltName: Full=mRNA (nucleoside-2'-O-)-methyltransferase {ECO:0000250|UniProtKB:P03523};
DE Short=N1-2'-O-MTase {ECO:0000250|UniProtKB:P03523};
DE Flags: Fragment;
GN Name=L;
OS Human respiratory syncytial virus.
OC Viruses; Riboviria; Orthornavirae; Negarnaviricota; Haploviricotina;
OC Monjiviricetes; Mononegavirales; Pneumoviridae; Orthopneumovirus.
OX NCBI_TaxID=11250;
OH NCBI_TaxID=9606; Homo sapiens (Human).
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC RNA].
RX PubMed=2440043; DOI=10.1073/pnas.84.15.5134;
RA Collins P.L., Olmsted R.A., Spriggs M.K., Johnson P.R., Buckler-White A.J.;
RT "Gene overlap and site-specific attenuation of transcription of the viral
RT polymerase L gene of human respiratory syncytial virus.";
RL Proc. Natl. Acad. Sci. U.S.A. 84:5134-5138(1987).
CC -!- FUNCTION: Responsible for RNA synthesis (replicase and transcriptase),
CC cap addition, and cap methylation. Performs also the polyadenylation of
CC subgenomic mRNAs by a stuttering mechanism at a slipery stop site
CC present at the end of viral genes. The template is composed of the
CC viral RNA tightly encapsidated by the nucleoprotein (N). The viral
CC polymerase binds to the genomic RNA at two differents sites in the 3'
CC leader promoter thereby initiating either genome replication or mRNA
CC transcription. In the transcription mode, the polymerase performs the
CC sequential transcription of all mRNAs using a termination-reinitiation
CC mechanism responding to gene start and gene end signals. Some
CC polymerase disengage from the template at each gene junction, resulting
CC in a decreasing abundance of transcripts from the 3' to the 5' end of
CC the genome. The first gene is the most transcribed, and the last the
CC least transcribed. Needs as cofactors the phosphoprotein for
CC processivity and the M2-1 anti-termination protein. Polyribonucleotidyl
CC transferase (PRNTase) adds the cap structure when the nascent RNA chain
CC length has reached few nucleotides (By similarity). Ribose 2'-O
CC methylation of viral mRNA cap precedes and facilitates subsequent
CC guanine-N-7 methylation (By similarity). In the replication mode, the
CC polymerase replicates the whole viral genome without recognizing the
CC gene end transcriptional signals. The ability of the polymerase to
CC override the gene end signals as it is producing the antigenome is
CC probably due to replicative RNA becoming encapsidated with
CC nucleoprotein as it is synthesized (By similarity).
CC {ECO:0000250|UniProtKB:P03523, ECO:0000250|UniProtKB:P28887}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=a ribonucleoside 5'-triphosphate + RNA(n) = diphosphate +
CC RNA(n+1); Xref=Rhea:RHEA:21248, Rhea:RHEA-COMP:14527, Rhea:RHEA-
CC COMP:17342, ChEBI:CHEBI:33019, ChEBI:CHEBI:61557, ChEBI:CHEBI:140395;
CC EC=2.7.7.48; Evidence={ECO:0000255|PROSITE-ProRule:PRU00539};
CC -!- CATALYTIC ACTIVITY:
CC Reaction=GTP + H2O = GDP + H(+) + phosphate; Xref=Rhea:RHEA:19669,
CC ChEBI:CHEBI:15377, ChEBI:CHEBI:15378, ChEBI:CHEBI:37565,
CC ChEBI:CHEBI:43474, ChEBI:CHEBI:58189;
CC Evidence={ECO:0000250|UniProtKB:P28887};
CC -!- CATALYTIC ACTIVITY:
CC Reaction=a 5'-end triphospho-adenylyl-adenylyl-cytidylyl-adenosine in
CC mRNA + GDP + H(+) = a 5'-end (5'-triphosphoguanosine)-adenylyl-
CC adenylyl-cytidylyl-adenosine in mRNA + diphosphate;
CC Xref=Rhea:RHEA:65436, Rhea:RHEA-COMP:16797, Rhea:RHEA-COMP:16799,
CC ChEBI:CHEBI:15378, ChEBI:CHEBI:33019, ChEBI:CHEBI:58189,
CC ChEBI:CHEBI:156484, ChEBI:CHEBI:156503; EC=2.7.7.88;
CC Evidence={ECO:0000250|UniProtKB:P28887};
CC -!- CATALYTIC ACTIVITY:
CC Reaction=a 5'-end (5'-triphosphoguanosine)-adenylyl-adenylyl-cytidylyl-
CC adenosine in mRNA + 2 S-adenosyl-L-methionine = a 5'-end (N(7)-methyl
CC 5'-triphosphoguanosine)-(2'-O-methyladenylyl)-adenylyl-cytidylyl-
CC adenosine in mRNA + H(+) + 2 S-adenosyl-L-homocysteine;
CC Xref=Rhea:RHEA:65376, Rhea:RHEA-COMP:16797, Rhea:RHEA-COMP:16798,
CC ChEBI:CHEBI:15378, ChEBI:CHEBI:57856, ChEBI:CHEBI:59789,
CC ChEBI:CHEBI:156483, ChEBI:CHEBI:156484; EC=2.1.1.375;
CC Evidence={ECO:0000250|UniProtKB:P03523};
CC -!- CATALYTIC ACTIVITY:
CC Reaction=a 5'-end (5'-triphosphoguanosine)-adenylyl-adenylyl-cytidylyl-
CC adenosine in mRNA + S-adenosyl-L-methionine = a 5'-end (5'-
CC triphosphoguanosine)-(2'-O-methyladenylyl)-adenylyl-cytidylyl-
CC adenosine in mRNA + H(+) + S-adenosyl-L-homocysteine;
CC Xref=Rhea:RHEA:65380, Rhea:RHEA-COMP:16797, Rhea:RHEA-COMP:16801,
CC ChEBI:CHEBI:15378, ChEBI:CHEBI:57856, ChEBI:CHEBI:59789,
CC ChEBI:CHEBI:156482, ChEBI:CHEBI:156484;
CC Evidence={ECO:0000250|UniProtKB:P03523};
CC -!- CATALYTIC ACTIVITY:
CC Reaction=a 5'-end (5'-triphosphoguanosine)-(2'-O-methyladenylyl)-
CC adenylyl-cytidylyl-adenosine in mRNA + S-adenosyl-L-methionine = a
CC 5'-end (N(7)-methyl 5'-triphosphoguanosine)-(2'-O-methyladenylyl)-
CC adenylyl-cytidylyl-adenosine in mRNA + S-adenosyl-L-homocysteine;
CC Xref=Rhea:RHEA:65440, Rhea:RHEA-COMP:16798, Rhea:RHEA-COMP:16801,
CC ChEBI:CHEBI:57856, ChEBI:CHEBI:59789, ChEBI:CHEBI:156482,
CC ChEBI:CHEBI:156483; Evidence={ECO:0000250|UniProtKB:P03523};
CC -!- COFACTOR:
CC Name=Mg(2+); Xref=ChEBI:CHEBI:18420;
CC Evidence={ECO:0000250|UniProtKB:P28887};
CC Note=For RNA-directed RNA polymerase activity. Mn(2+) can stimulate de
CC novo initiation but it is inefficient at supporting elongation of de
CC novo initiated RNA. {ECO:0000250|UniProtKB:P28887};
CC -!- SUBUNIT: Interacts with the phosphoprotein (via C-terminus); the
CC association of P and L forms the polymerase complex.
CC {ECO:0000250|UniProtKB:P28887}.
CC -!- SUBCELLULAR LOCATION: Virion {ECO:0000250|UniProtKB:P28887}. Host
CC cytoplasm {ECO:0000250|UniProtKB:P28887}. Note=Localizes in cytoplasmic
CC inclusion bodies. {ECO:0000250|UniProtKB:P28887}.
CC -!- DOMAIN: Contains an RNA-dependent RNA polymerase (RdRp) domain, a
CC polyribonucleotidyl transferase (PRNTase or capping) domain and a
CC methyltransferase (MTase) domain. {ECO:0000250|UniProtKB:P28887}.
CC -!- SIMILARITY: Belongs to the paramyxovirus L protein family.
CC {ECO:0000305}.
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DR EMBL; M17245; AAA47417.1; -; Genomic_RNA.
DR SMR; P20894; -.
DR GO; GO:0030430; C:host cell cytoplasm; IEA:UniProtKB-SubCell.
DR GO; GO:0005524; F:ATP binding; IEA:UniProtKB-KW.
DR GO; GO:0003924; F:GTPase activity; IEA:RHEA.
DR GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR GO; GO:0004482; F:mRNA (guanine-N7-)-methyltransferase activity; IEA:InterPro.
DR GO; GO:0003968; F:RNA-directed 5'-3' RNA polymerase activity; IEA:UniProtKB-KW.
DR InterPro; IPR014023; Mononeg_RNA_pol_cat.
DR Pfam; PF00946; Mononeg_RNA_pol; 1.
PE 3: Inferred from homology;
KW ATP-binding; Host cytoplasm; Hydrolase; Magnesium; Metal-binding;
KW Methyltransferase; mRNA capping; mRNA processing; Multifunctional enzyme;
KW Nucleotide-binding; Nucleotidyltransferase; RNA-directed RNA polymerase;
KW S-adenosyl-L-methionine; Transferase; Viral RNA replication; Virion.
FT CHAIN 1..>81
FT /note="RNA-directed RNA polymerase L"
FT /id="PRO_0000142744"
FT NON_TER 81
SQ SEQUENCE 81 AA; 9182 MW; 8A7F5588BF6DBB06 CRC64;
MDPIINGNSA NVYLTDSYLK GVISFSECNA LGSYIFNGPY LKNDYTNLIS RQNPLIEHMN
LKKLNITQSL ISKYHKGEIK L
