ID   PB2_I77AG               Reviewed;         759 AA.
AC   P26104;
DT   01-MAY-1992, integrated into UniProtKB/Swiss-Prot.
DT   01-MAY-1992, sequence version 1.
DT   03-AUG-2022, entry version 95.
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/Budgerigar/Hokkaido/1/1977 H4N6).
OC   Viruses; Riboviria; Orthornavirae; Negarnaviricota; Polyploviricotina;
OC   Insthoviricetes; Articulavirales; Orthomyxoviridae; Alphainfluenzavirus.
OX   NCBI_TaxID=385587;
OH   NCBI_TaxID=8782; Aves.
OH   NCBI_TaxID=9823; Sus scrofa (Pig).
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; M73523; AAA43137.1; -; Genomic_RNA.
DR   SMR; P26104; -.
DR   PRIDE; P26104; -.
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_0000078813"
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;  85872 MW;  CAF2E9D5EB17D83A CRC64;
     MERIKGLRDL MSQSRTREIL TKTTVDHMAI IKKYTSGRQE KNPALRMKWM MAMKYPITAD
     KRIMEMIPER NEQGQTLWSK TNDAGSDRVM VSPLAVTWWN RNGPTTSTIH YPKVYKTYFE
     KVERLRHGTF GPVHFRNQVK IRRRVDINPG HADLSAKEAQ DVIMEVVFPN EVGAKILTSE
     SQLTITKEKK EELQDCKIAP LMVAYMLERE LVRKTRFLPV AGGTSSVYIE VLHLTQGTCW
     EQMYTPGGEV RNDDVDQSLI IAARNIVRRA TVSTDPLSSL LEMCHSTQIG GVRMVDILRQ
     NPTEEQAVDI CKAAMGLRIS SSFSFGGFTF KRTSGSSVKR EEEILTGNLQ TLKIRVHEGY
     EEFTMVGRRA TAILRKATRR LIQLIVSGRD EQSIAEAIIV AMVFSQDDCM IKAVRGDLNF
     VNRANQRLNP MHQLLRHFQK DAKVLFQNWG IEPIDNVMGM IGILPDMTPS TEMSLRGVRV
     SKMGVDEYSS TERVVVSIDR FLRVRDQRGN VLLSPEEVSE TQGTEKLTIT YSSSMMWEIN
     GSESVLVNTY QWIIRNWETV KIQWSQDPTM LYNKMEFEPF QSLVPKAARG KYSGFVRTLF
     QQMRDVLGTF DTVQIIKLLP FAAAPPEQSR MQFSSLTVNV RGSGMRILVR GNSPVFNYNK
     ATKRLTVLGK DAGALTEDPD EGTAGVESAV LRGFLILGKE DKRYGPALSI NELSNLAKGE
     KANVLIGQGD VVLVMKRKRD SSILTDSQTA TKRLRMAIN