ID RDRP_I88A7 Reviewed; 757 AA. AC P16514; DT 01-AUG-1990, integrated into UniProtKB/Swiss-Prot. DT 01-AUG-1990, sequence version 1. DT 08-NOV-2023, entry version 88. DE RecName: Full=RNA-directed RNA polymerase catalytic subunit {ECO:0000255|HAMAP-Rule:MF_04065}; DE EC=2.7.7.48 {ECO:0000255|HAMAP-Rule:MF_04065}; DE AltName: Full=Polymerase basic protein 1 {ECO:0000255|HAMAP-Rule:MF_04065}; DE Short=PB1 {ECO:0000255|HAMAP-Rule:MF_04065}; DE AltName: Full=RNA-directed RNA polymerase subunit P1 {ECO:0000255|HAMAP-Rule:MF_04065}; GN Name=PB1 {ECO:0000255|HAMAP-Rule:MF_04065}; OS Influenza A virus (strain A/Wisconsin/3523/1988 H1N1). OC Viruses; Riboviria; Orthornavirae; Negarnaviricota; Polyploviricotina; OC Insthoviricetes; Articulavirales; Orthomyxoviridae; Alphainfluenzavirus; OC Alphainfluenzavirus influenzae; Influenza A virus. OX NCBI_TaxID=380346; OH NCBI_TaxID=8782; Aves. OH NCBI_TaxID=9606; Homo sapiens (Human). OH NCBI_TaxID=9823; Sus scrofa (Pig). RN [1] RP NUCLEOTIDE SEQUENCE [GENOMIC RNA]. RX PubMed=2795713; DOI=10.1128/jvi.63.11.4603-4608.1989; RA Kawaoka Y., Krauss S., Webster R.G.; RT "Avian-to-human transmission of the PB1 gene of influenza A viruses in the RT 1957 and 1968 pandemics."; RL J. Virol. 63:4603-4608(1989). CC -!- FUNCTION: RNA-dependent RNA polymerase which is responsible for CC replication and transcription of virus RNA segments. The transcription CC of viral mRNAs occurs by a unique mechanism called cap-snatching. 5' CC methylated caps of cellular mRNAs are cleaved after 10-13 nucleotides CC by PA. In turn, these short capped RNAs are used as primers by PB1 for CC transcription of viral mRNAs. During virus replication, PB1 initiates CC RNA synthesis and copy vRNA into complementary RNA (cRNA) which in turn CC serves as a template for the production of more vRNAs. CC {ECO:0000255|HAMAP-Rule:MF_04065}. 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|HAMAP-Rule:MF_04065}; CC -!- SUBUNIT: Influenza RNA polymerase is composed of three subunits: PB1, CC PB2 and PA. Interacts (via N-terminus) with PA (via C-terminus). CC Interacts (via C-terminus) with PB2 (via N-terminus); this interaction CC is essential for transcription initiation. Interacts (via C-terminus) CC with human PKP2 (via N-terminus); the interaction competitively CC inhibits the interaction between the RNA polymerase subunits PB1 and CC PB2 (By similarity). {ECO:0000250|UniProtKB:P03431, ECO:0000255|HAMAP- CC Rule:MF_04065}. CC -!- SUBCELLULAR LOCATION: Host nucleus {ECO:0000255|HAMAP-Rule:MF_04065}. CC Host cytoplasm {ECO:0000255|HAMAP-Rule:MF_04065}. CC -!- PTM: Phosphorylated by host PRKCA. {ECO:0000255|HAMAP-Rule:MF_04065}. CC -!- SIMILARITY: Belongs to the influenza viruses polymerase PB1 family. CC {ECO:0000255|HAMAP-Rule:MF_04065}. 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; M25934; AAA43643.1; -; Genomic_RNA. DR SMR; P16514; -. DR GO; GO:0030430; C:host cell cytoplasm; IEA:UniProtKB-SubCell. DR GO; GO:0042025; C:host cell nucleus; IEA:UniProtKB-SubCell. DR GO; GO:0000166; F:nucleotide binding; IEA:UniProtKB-UniRule. DR GO; GO:0003723; F:RNA binding; IEA:InterPro. DR GO; GO:0003968; F:RNA-dependent RNA polymerase activity; IEA:UniProtKB-UniRule. DR GO; GO:0006351; P:DNA-templated transcription; IEA:UniProtKB-UniRule. DR GO; GO:0039523; P:suppression by virus of host mRNA transcription via inhibition of RNA polymerase II activity; IEA:UniProtKB-UniRule. DR GO; GO:0039694; P:viral RNA genome replication; IEA:UniProtKB-UniRule. DR GO; GO:0019083; P:viral transcription; IEA:UniProtKB-KW. DR Gene3D; 6.10.140.720; -; 1. DR HAMAP; MF_04065; INFV_RDRP; 1. DR InterPro; IPR007099; RNA-dir_pol_NSvirus. DR InterPro; IPR001407; RNA_pol_PB1_influenza. DR Pfam; PF00602; Flu_PB1; 1. DR PIRSF; PIRSF000827; RdRPol_OMV; 1. DR PROSITE; PS50525; RDRP_SSRNA_NEG_SEG; 1. PE 3: Inferred from homology; KW Eukaryotic host gene expression shutoff by virus; KW Eukaryotic host transcription shutoff by virus; Host cytoplasm; KW Host gene expression shutoff by virus; Host nucleus; KW Host-virus interaction; Inhibition of host RNA polymerase II by virus; KW Nucleotide-binding; Nucleotidyltransferase; Phosphoprotein; KW RNA-directed RNA polymerase; Transferase; Viral RNA replication; KW Viral transcription. FT CHAIN 1..757 FT /note="RNA-directed RNA polymerase catalytic subunit" FT /id="PRO_0000078768" FT DOMAIN 286..483 FT /note="RdRp catalytic" FT /evidence="ECO:0000255|HAMAP-Rule:MF_04065" FT REGION 249..256 FT /note="Promoter-binding site" FT /evidence="ECO:0000255|HAMAP-Rule:MF_04065" FT MOTIF 187..195 FT /note="Nuclear localization signal" FT /evidence="ECO:0000255|HAMAP-Rule:MF_04065" FT MOTIF 203..216 FT /note="Nuclear localization signal" FT /evidence="ECO:0000255|HAMAP-Rule:MF_04065" SQ SEQUENCE 757 AA; 86475 MW; DDA6EDEFCAB901EF CRC64; MDVNPTLLFL KVPAQNAIST TFPYTGDPPY SHGTGTGYTM DTVNRTHQYS ERGKWTINTE TGAPQLNPID GPLPEDNEPT GYAQTDCVLE AMAFLEKSHP GIFENSCLET MEVVQQTRVD KLTQGRQTFD WTLNRNQPAA TALANTIEVF RLNGLTTSES GRLIDFLKDV MESMEKEEME IVTHFQRKRR VRDNMTKKMV TQRTIGKKKQ KLNRRGYLIR ALTLNTMTKD AERGKLKRRA IATPGMQIRG FVYFVETLAR SICEKLEQSG LPVGGNEKKA KLANVVRKMM TNSQDTELSF TITGDNTKWN ENQNPRMFLA MITYITRNQP EWFRNVLSVA PIMFSNKMAR LGKGYMFESK NMKLRTQIPA EMLSSIDLRY FNDSTRRKIE KIRPLLIEGA ASLSPGMMMG MFNMLSTVLG VSILNLGQKE YTKTSYWWDG LQSSDDFALI VNAPNHEGIQ AGVDRFYRTC KLLGINMSKK KSYINRTGTF EFTSFFYRYG FVANFSMELP SFGVSGINES ADMSIGVTVI KNNMINNDLG PATAQMALQL FIKDYRYTYR CHRGDTQIQT RRSFEIKKLW DQTRSKAGLL VSDGGPNLYN IRNLHIPEVC LKWELMDKDY QGRLCNPLNP FVSHKEIESV NNAVVMPSHG PAKTMEYDAV ATTHSWVPKR NRSILNTSQR GILEDEQMYQ KCCNLFEKFF PSSSYRRPVG ISSMVEAMVS RARIDARIDF ESGRIKKEDF AEIMKICSTI EDLRRQK //