Q83626 · Q83626_MEASF
- ProteinRNA-directed RNA polymerase L
- StatusUniProtKB unreviewed (TrEMBL)
- Amino acids2183 (go to sequence)
- Protein existenceInferred from homology
- Annotation score4/5
Function
function
RNA-directed RNA polymerase that catalyzes the replication of viral genomic RNA. The template is composed of the viral RNA tightly encapsidated by the nucleoprotein (N). The replicase mode is dependent on intracellular N protein concentration. In this mode, the polymerase replicates the whole viral genome without recognizing transcriptional signals, and the replicated genome is not caped or polyadenylated.
RNA-directed RNA polymerase that catalyzes the transcription of viral mRNAs, their capping and polyadenylation. The template is composed of the viral RNA tightly encapsidated by the nucleoprotein (N). The viral polymerase binds to the genomic RNA at the 3' leader promoter, and transcribes subsequently all viral mRNAs with a decreasing efficiency. The first gene is the most transcribed, and the last the least transcribed. The viral phosphoprotein acts as a processivity factor. Capping is concommitant with initiation of mRNA transcription. Indeed, a GDP polyribonucleotidyl transferase (PRNTase) adds the cap structure when the nascent RNA chain length has reached few nucleotides. Ribose 2'-O methylation of viral mRNA cap precedes and facilitates subsequent guanine-N-7 methylation, both activities being carried by the viral polymerase. Polyadenylation of mRNAs occur by a stuttering mechanism at a slipery stop site present at the end viral genes. After finishing transcription of a mRNA, the polymerase can resume transcription of the downstream gene.
Catalytic activity
- GTP + H2O = GDP + phosphate + H+
- a 5'-end (5'-triphosphoguanosine)-(2'-O-methyladenylyl)-adenylyl-cytidylyl-adenosine in mRNA + S-adenosyl-L-methionine = a 5'-end (N7-methyl 5'-triphosphoguanosine)-(2'-O-methyladenylyl)-adenylyl-cytidylyl-adenosine in mRNA + S-adenosyl-L-homocysteine
- a 5'-end (5'-triphosphoguanosine)-adenylyl-adenylyl-cytidylyl-adenosine in mRNA + S-adenosyl-L-methionine = a 5'-end (5'-triphosphoguanosine)-(2'-O-methyladenylyl)-adenylyl-cytidylyl-adenosine in mRNA + S-adenosyl-L-homocysteine + H+
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | cytoplasm | |
Cellular Component | host cell cytoplasm | |
Cellular Component | virion component | |
Molecular Function | ATP binding | |
Molecular Function | GTPase activity | |
Molecular Function | mRNA 5'-cap (guanine-N7-)-methyltransferase activity | |
Molecular Function | RNA-dependent RNA polymerase activity |
Keywords
- Molecular function
- Biological process
- Ligand
Names & Taxonomy
Protein names
- Recommended nameRNA-directed RNA polymerase L
- Short namesProtein L
- Alternative names
Including 5 domains:
- Recommended nameRNA-directed RNA polymerase
- EC number
- Recommended nameGTP phosphohydrolase
- EC number
- Recommended nameGDP polyribonucleotidyltransferase
- EC number
- Alternative names
- Recommended namemRNA (nucleoside-2'-O-)-methyltransferase
- EC number
- Short namesN1-2'-O-MTase
- Recommended namemRNA (guanine-N(7)-)-methyltransferase
- Short namesG-N7-MTase
Organism names
- Strain
- Taxonomic lineageViruses > Riboviria > Orthornavirae > Negarnaviricota > Haploviricotina > Monjiviricetes > Mononegavirales > Paramyxoviridae > Orthoparamyxovirinae > Morbillivirus > Morbillivirus hominis > Measles morbillivirus
- Virus hosts
Accessions
- Primary accessionQ83626
Proteomes
Subcellular Location
Interaction
Subunit
Interacts with the P protein.
Structure
Family & Domains
Features
Showing features for domain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Domain | 656-840 | RdRp catalytic | ||||
Sequence: VSAFITTDLKKYCLNWRYETISLFAQRLNEIYGLPSFFQWLHKRLETSVLYVSDPHCPPDLDAHIPLYKVPNDQIFIKYPMGGIEGYCQKLWTISTIPYLYLAAYESGVRIASLVQGDNQTIAVTKRVPSTWPYNLKKREAARVTRDYFVILRQRLHDIGHHLKANETIVSSHFFVYSKGIYYDG | ||||||
Domain | 1755-1958 | Mononegavirus-type SAM-dependent 2'-O-MTase | ||||
Sequence: RRIGLNSSACYKAVEISTLIRRCLEPGEDGLFLGEGSGSMLITYKEILKLSKCFYNSGVSANSRSGQRELAPYPSEVGLVEHRMGVGNIVKVLFNGRPEVTWVGSVDCFNFIVSNIPTSSVGFIHSDIETLPDKDTIEKLEELAAILSMALLLGKIGSILVIKLMPFSGDFVQGFISYVGSHYREVNLVYPRYSNFISTESYLV |
Sequence similarities
Belongs to the paramyxovirus L protein family.
Family and domain databases
Sequence
- Sequence statusComplete
- Length2,183
- Mass (Da)247,595
- Last updated1996-11-01 v1
- ChecksumCE3E40FB6297DA6A