ID   PB2_I86A2               Reviewed;         759 AA.
AC   P26105;
DT   01-MAY-1992, integrated into UniProtKB/Swiss-Prot.
DT   01-MAY-1992, sequence version 1.
DT   03-AUG-2022, entry version 94.
DE   RecName: Full=Polymerase basic protein 2 {ECO:0000255|HAMAP-Rule:MF_04062};
DE   AltName: Full=RNA-directed RNA polymerase subunit P3 {ECO:0000255|HAMAP-Rule:MF_04062};
GN   Name=PB2 {ECO:0000255|HAMAP-Rule:MF_04062};
OS   Influenza A virus (strain A/Equine/Kentucky/2/1986 H3N8).
OC   Viruses; Riboviria; Orthornavirae; Negarnaviricota; Polyploviricotina;
OC   Insthoviricetes; Articulavirales; Orthomyxoviridae; Alphainfluenzavirus.
OX   NCBI_TaxID=385605;
OH   NCBI_TaxID=8782; Aves.
OH   NCBI_TaxID=9796; Equus caballus (Horse).
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC RNA].
RX   PubMed=2398532; DOI=10.1128/jvi.64.10.4893-4902.1990;
RA   Gorman O.T., Donis R.O., Kawaoka Y., Webster R.G.;
RT   "Evolution of influenza A virus PB2 genes: implications for evolution of
RT   the ribonucleoprotein complex and origin of human influenza A virus.";
RL   J. Virol. 64:4893-4902(1990).
CC   -!- FUNCTION: Plays an essential role in transcription initiation and cap-
CC       stealing mechanism, in which cellular capped pre-mRNAs are used to
CC       generate primers for viral transcription. Recognizes and binds the 7-
CC       methylguanosine-containing cap of the target pre-RNA which is
CC       subsequently cleaved after 10-13 nucleotides by the viral protein PA.
CC       Plays a role in the initiation of the viral genome replication and
CC       modulates the activity of the ribonucleoprotein (RNP) complex.
CC       {ECO:0000255|HAMAP-Rule:MF_04062}.
CC   -!- SUBUNIT: Influenza RNA polymerase is composed of three subunits: PB1,
CC       PB2 and PA. Interacts (via N-terminus) with PB1 (via C-terminus).
CC       Interacts with nucleoprotein NP (via N-terminus). {ECO:0000255|HAMAP-
CC       Rule:MF_04062}.
CC   -!- SUBCELLULAR LOCATION: Virion {ECO:0000255|HAMAP-Rule:MF_04062}. Host
CC       nucleus {ECO:0000255|HAMAP-Rule:MF_04062}.
CC   -!- SIMILARITY: Belongs to the influenza viruses PB2 family.
CC       {ECO:0000255|HAMAP-Rule:MF_04062}.
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DR   EMBL; M73526; AAA43133.1; -; Genomic_RNA.
DR   SMR; P26105; -.
DR   GO; GO:0042025; C:host cell nucleus; IEA:UniProtKB-SubCell.
DR   GO; GO:0044423; C:virion component; IEA:UniProtKB-UniRule.
DR   GO; GO:0003723; F:RNA binding; IEA:UniProtKB-UniRule.
DR   GO; GO:0003968; F:RNA-directed 5'-3' RNA polymerase activity; IEA:UniProtKB-UniRule.
DR   GO; GO:0006370; P:7-methylguanosine mRNA capping; IEA:UniProtKB-UniRule.
DR   GO; GO:0075526; P:cap snatching; 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:0006351; P:transcription, DNA-templated; IEA:UniProtKB-UniRule.
DR   GO; GO:0039694; P:viral RNA genome replication; IEA:InterPro.
DR   Gene3D; 3.30.30.90; -; 1.
DR   HAMAP; MF_04062; INV_PB2; 1.
DR   InterPro; IPR001591; INV_PB2.
DR   InterPro; IPR037258; PDB2_C.
DR   Pfam; PF00604; Flu_PB2; 1.
DR   SUPFAM; SSF160453; SSF160453; 1.
PE   3: Inferred from homology;
KW   Cap snatching; Eukaryotic host gene expression shutoff by virus;
KW   Eukaryotic host transcription shutoff by virus;
KW   Host gene expression shutoff by virus; Host nucleus;
KW   Host-virus interaction; Inhibition of host RNA polymerase II by virus;
KW   mRNA capping; mRNA processing; Viral transcription; Virion.
FT   CHAIN           1..759
FT                   /note="Polymerase basic protein 2"
FT                   /id="PRO_0000078821"
FT   MOTIF           736..739
FT                   /note="Nuclear localization signal"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_04062"
FT   SITE            627
FT                   /note="Avian adaptation"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_04062"
SQ   SEQUENCE   759 AA;  86051 MW;  DB468F5AC6C97A8A CRC64;
     MERIKELRDL MSQSRTREIL TKTTVDHMAI IKKYTSGRQE KNPALRMKWM MAMKYPITAD
     KRIMEMIPER NEQGQTLWSK TNDAGSDRVM VSPLAVTWWN RNGPTTSTIH YPKVYKTYFE
     KVERLKHGTF GPVHFRNQVK IRRRVDVNPG HADLSAKEAQ DVIMEVVFPN EVGARILTSE
     SQLTITKEKK EELQDCKIAP LMVAYMLERE LVRKTRFLPV AGGTSSVYIE VLHLTQGTCW
     EQMYTPGGEV RNDDIDQSLI IAARNIVKRA TVSADPLASL LEMCHSTQIG GIRMVDILKQ
     NPTEEQAVDI CKAAMGLRIS SSFSFGGFTF KRTSGSSVKR EEEMLTGNLQ TLKIRVHEGY
     EEFTMVGRRA TAILRKTTRR LIQLIVSGRD EQSIAEAIIV AMVFSQEDCM IKAVRGDLNF
     VNRANQRLNP MHQLLRHFQK DAKVLFQNWG IEPIDNVMGM IGILPDMTPS TEMSLRGVRV
     SKMGVDEYSS TERVVVSIDR FLRVRDQRGN ILLSPEEVSE TQGTEKLTII YSSSMMWEIN
     GPESVLVNTY QWIIRNWEIV KIQWSQDPTM LYNKIEFEPF QSLVPRATRS QYSGFVRTLF
     QQMRDVLGTF DTAQIIKLLP FAAAPPEQSR MQFSSLTVNV RGSGMRILVR GNSPVFNYNK
     ATKRLTVLGK DAGALTEDPD EGTAGVESAV LRGFLILGKE NKRYGPALSI NELSKLTKGE
     KANVLIGQGD VVLVMKRKRD SSILTDSQTA TKRIRMAIN