ID   DPOL_HBVF1              Reviewed;         843 AA.
AC   Q05486;
DT   01-NOV-1995, integrated into UniProtKB/Swiss-Prot.
DT   01-NOV-1995, sequence version 1.
DT   16-JUN-2009, entry version 49.
DE   RecName: Full=Protein P;
DE   Includes:
DE     RecName: Full=DNA-directed DNA polymerase;
DE              EC=2.7.7.7;
DE   Includes:
DE     RecName: Full=RNA-directed DNA polymerase;
DE              EC=2.7.7.49;
DE   Includes:
DE     RecName: Full=Ribonuclease H;
DE              EC=3.1.26.4;
GN   Name=P;
OS   Hepatitis B virus genotype F2 (isolate Brazil/w4B) (HBV-F).
OC   Viruses; Retro-transcribing viruses; Hepadnaviridae;
OC   Orthohepadnavirus.
OX   NCBI_TaxID=45410;
OH   NCBI_TaxID=9598; Pan troglodytes (Chimpanzee).
OH   NCBI_TaxID=9606; Homo sapiens (Human).
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   MEDLINE=93346970; PubMed=8345355;
RA   Naumann H., Schaefer S., Yoshida C.F.T., Gaspar A.M.C., Repp R.,
RA   Gerlich W.H.;
RT   "Identification of a new hepatitis B virus (HBV) genotype from Brazil
RT   that expresses HBV surface antigen subtype adw4.";
RL   J. Gen. Virol. 74:1627-1632(1993).
RN   [2]
RP   REVIEW.
RX   PubMed=17206754;
RA   Beck J., Nassal M.;
RT   "Hepatitis B virus replication.";
RL   World J. Gastroenterol. 13:48-64(2007).
CC   -!- FUNCTION: Multifunctional enzyme that converts the viral RNA
CC       genome into dsDNA in viral cytoplasmic capsids. This enzyme
CC       displays a DNA polymerase activity that can copy either DNA or RNA
CC       templates, and a ribonuclease H (RNase H) activity that cleaves
CC       the RNA strand of RNA-DNA heteroduplexes in a partially processive
CC       3'- to 5'-endonucleasic mode. Neo-synthesized pregenomic RNA
CC       (pgRNA) are encapsidated together with the P protein, and reverse-
CC       transcribed inside the nucleocapsid. Initiation of reverse-
CC       transcription occurs first by binding the epsilon loop on the
CC       pgRNA genome, and is initiated by protein priming, thereby the 5'-
CC       end of (-)DNA is covalently linked to P protein. Partial (+)DNA is
CC       synthesized from the (-)DNA template and generates the relaxed
CC       circular DNA (RC-DNA) genome. After budding and infection, the RC-
CC       DNA migrates in the nucleus, and is converted into a plasmid-like
CC       covalently closed circular DNA (cccDNA). The activity of P protein
CC       does not seem to be necessary for cccDNA generation, and is
CC       presumably released from (+)DNA by host nuclear DNA repair
CC       machinery (By similarity).
CC   -!- CATALYTIC ACTIVITY: Deoxynucleoside triphosphate + DNA(n) =
CC       diphosphate + DNA(n+1).
CC   -!- CATALYTIC ACTIVITY: Endonucleolytic cleavage to 5'-
CC       phosphomonoester.
CC   -!- ENZYME REGULATION: Activated by host HSP70 and HSP40 in vitro to
CC       be able to bind the epsilon loop of the pgRNA. Because deletion of
CC       the RNase H region renders the protein partly chaperone-
CC       independent, the chaperones may be needed indirectly to releive
CC       occlusion of the RNA-binding site by this domain. Inhibited by
CC       several reverse-transcriptase inhibitors: Lamivudine, Adefovir and
CC       Entecavir (By similarity).
CC   -!- DOMAIN: Terminal protein domain (TP) is hepadnavirus-specific.
CC       Spacer domain is highly variable and separates the TP and RT
CC       domains. Polymerase/reverse-transcriptase domain (RT) and
CC       ribonuclease H domain (RH) are similar to retrovirus reverse
CC       transcriptase/RNase H (By similarity).
CC   -!- DOMAIN: The polymerase/reverse transcriptase (RT) and ribonuclease
CC       H (RH) domains are structured in five subdomains: finger, palm,
CC       thumb, connection and RNase H. Within the palm subdomain, the
CC       'primer grip' region is thought to be involved in the positioning
CC       of the primer terminus for accommodating the incoming nucleotide.
CC       The RH domain stabilizes the association of RT with primer-
CC       template (By similarity).
CC   -!- MISCELLANEOUS: Hepadnaviral virions contain probably just one P
CC       protein molecule per particle (By similarity).
CC   -!- SIMILARITY: Belongs to the hepadnaviridae P protein family.
CC   -!- SIMILARITY: Contains 1 reverse transcriptase domain.
CC   -!- WEB RESOURCE: Name=HepSEQ; Note=Hepatitis virus B database;
CC       URL="http://www.hpa-bioinfodatabases.org.uk/hepatitis_open/main.php";
CC   -----------------------------------------------------------------------
CC   Copyrighted by the UniProt Consortium, see http://www.uniprot.org/terms
CC   Distributed under the Creative Commons Attribution-NoDerivs License
CC   -----------------------------------------------------------------------
DR   EMBL; X69798; CAA49456.1; -; Genomic_DNA.
DR   PIR; JQ2229; JQ2229.
DR   DrugBank; DB00709; Lamivudine.
DR   DrugBank; DB01265; Telbivudine.
DR   GO; GO:0003677; F:DNA binding; IEA:UniProtKB-KW.
DR   GO; GO:0003887; F:DNA-directed DNA polymerase activity; IEA:UniProtKB-KW.
DR   GO; GO:0000287; F:magnesium ion binding; IEA:UniProtKB-KW.
DR   GO; GO:0004523; F:ribonuclease H activity; IEA:EC.
DR   GO; GO:0003723; F:RNA binding; IEA:InterPro.
DR   GO; GO:0003964; F:RNA-directed DNA polymerase activity; IEA:UniProtKB-KW.
DR   GO; GO:0006278; P:RNA-dependent DNA replication; IEA:InterPro.
DR   InterPro; IPR000477; DNA_pol_RVTase.
DR   InterPro; IPR001462; DNApol_viral_C.
DR   InterPro; IPR000201; DNApol_viral_N.
DR   Pfam; PF00336; DNA_pol_viral_C; 1.
DR   Pfam; PF00242; DNA_pol_viral_N; 1.
DR   Pfam; PF00078; RVT_1; 2.
DR   ProDom; PD000814; DNApol_viral_C; 1.
DR   PROSITE; PS50878; RT_POL; 1.
PE   3: Inferred from homology;
KW   Complete proteome; DNA replication; DNA-binding;
KW   DNA-directed DNA polymerase; Endonuclease; Hydrolase; Magnesium;
KW   Metal-binding; Multifunctional enzyme; Nuclease;
KW   Nucleotidyltransferase; RNA-directed DNA polymerase; Transferase.
FT   CHAIN         1    843       Protein P.
FT                                /FTId=PRO_0000222338.
FT   DOMAIN      357    600       Reverse transcriptase.
FT   REGION        1    177       Terminal protein domain (TP) (By
FT                                similarity).
FT   REGION      178    346       Spacer (By similarity).
FT   REGION      347    690       Polymerase/reverse transcriptase domain
FT                                (RT) (By similarity).
FT   REGION      691    843       RnaseH domain (RH) (By similarity).
FT   METAL       429    429       Magnesium; catalytic (By similarity).
FT   METAL       551    551       Magnesium; catalytic (By similarity).
FT   METAL       552    552       Magnesium; catalytic (By similarity).
FT   SITE         63     63       Priming of reverse-transcription by
FT                                covalently linking the first nucleotide
FT                                of the (-)DNA (By similarity).
SQ   SEQUENCE   843 AA;  94258 MW;  8B31830B05A586B4 CRC64;
     MPLSYPHFRK LLLLDDEAGP LEEELPRLAD EDLNRRVAAD LNLQLPNVSI PWTHKVGNFT
     GLYSSTVPAF NPNWSTPSFP DIHLHQDLIS KCEQFVGPLT KNELRRLKLV MPARFYPKVT
     KYFPMDKGIK PYYPEHAVNH YFKTRHYLHT LWKAGILYKR ESTRSASFCG SPYSWEQELQ
     HGSTSLNDTK RHGTESLCAQ SSGILSRPSA GSAIQSKFQQ SRLGLQHKQG QLANGKQGRS
     GRLRSRVHTP TRWPAGVEPS STRCVNNLAS RSASCFHQSA VREKANPSLS TSKRHTSTGN
     AVELNPVPPS SVGSQGKGSV LPCWWLQFRD TEPCSDYCLS HIINLLEDWG PCYEHGQHYI
     RTPRTPARVT GGVFLVDKNP HNTTESRLVV DFSQFSRGTT RVSWPKFAVP NLQSLTNLLS
     SNLSWLSLDV SAAFYHLPLH PAAMPHLLVG SSGLSRYVAR LSSTSRIHDH QHGTLQNLHN
     SCTRNLYVSL LLLFQTLGRK LHLYSHPIIL GFRKIPMGVG LSPFLLAQFT SAICSVVRRA
     FPHCLAFSYM DDLVLGAKSV QHLESLYTAV TNFLLSVGIH LNTSKTKRWG YSLHFMGYVI
     GSWGSLPQDH IVHKIKECFR KLPVNRPIDW KVCQRIVGLL GFAAPFTQCG YPALMPLYAC
     ITAKQAFVFS PTYKAFLCKQ YMNLYPVARQ RPGLCQVFAD ATPTGWGLAI GHQRMRGTFV
     APLPIHTAEL LAACFARSRS GATLIGTDNS VVLSRKYTSF PWLLGCAANW ILRGTSFVYV
     PSALNPADDP SRGRLGLYRP LLRLPFQPTT GRTSLYADSP SVPSHLPDRV HFASPLHVAW
     RPP
//