DPOL_HHBV
ID DPOL_HHBV Reviewed; 788 AA.
AC P13846;
DT 01-JAN-1990, integrated into UniProtKB/Swiss-Prot.
DT 01-JAN-1990, sequence version 1.
DT 03-AUG-2022, entry version 95.
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 Heron hepatitis B virus (HHBV).
OC Viruses; Riboviria; Pararnavirae; Artverviricota; Revtraviricetes;
OC Blubervirales; Hepadnaviridae; Avihepadnavirus.
OX NCBI_TaxID=28300;
OH NCBI_TaxID=8899; Ardeidae (herons).
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX PubMed=3418788; DOI=10.1128/jvi.62.10.3832-3839.1988;
RA Sprengel R., Kaleta E.F., Will H.;
RT "Isolation and characterization of a hepatitis B virus endemic in herons.";
RL J. Virol. 62:3832-3839(1988).
RN [2]
RP REVIEW.
RX PubMed=17206754; DOI=10.3748/wjg.v13.i1.48;
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 genome
CC into dsDNA in viral cytoplasmic capsids. This enzyme displays a DNA
CC polymerase activity that can copy either DNA or RNA templates, and a
CC ribonuclease H (RNase H) activity that cleaves the RNA strand of RNA-
CC DNA heteroduplexes in a partially processive 3'- to 5'-endonucleasic
CC mode. Neo-synthesized pregenomic RNA (pgRNA) are encapsidated together
CC with the P protein, and reverse-transcribed inside the nucleocapsid.
CC Initiation of reverse-transcription occurs first by binding the epsilon
CC loop on the pgRNA genome, and is initiated by protein priming, thereby
CC the 5'-end of (-)DNA is covalently linked to P protein. Partial (+)DNA
CC is synthesized from the (-)DNA template and generates the relaxed
CC circular DNA (RC-DNA) genome. After budding and infection, the RC-DNA
CC migrates in the nucleus, and is converted into a plasmid-like
CC covalently closed circular DNA (cccDNA). The activity of P protein does
CC not seem to be necessary for cccDNA generation, and is presumably
CC released from (+)DNA by host nuclear DNA repair machinery (By
CC similarity). {ECO:0000250}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=a 2'-deoxyribonucleoside 5'-triphosphate + DNA(n) =
CC diphosphate + DNA(n+1); Xref=Rhea:RHEA:22508, Rhea:RHEA-COMP:17339,
CC Rhea:RHEA-COMP:17340, ChEBI:CHEBI:33019, ChEBI:CHEBI:61560,
CC ChEBI:CHEBI:173112; EC=2.7.7.7; Evidence={ECO:0000255|PROSITE-
CC ProRule:PRU00405};
CC -!- CATALYTIC ACTIVITY:
CC Reaction=a 2'-deoxyribonucleoside 5'-triphosphate + DNA(n) =
CC diphosphate + DNA(n+1); Xref=Rhea:RHEA:22508, Rhea:RHEA-COMP:17339,
CC Rhea:RHEA-COMP:17340, ChEBI:CHEBI:33019, ChEBI:CHEBI:61560,
CC ChEBI:CHEBI:173112; EC=2.7.7.49; Evidence={ECO:0000255|PROSITE-
CC ProRule:PRU00405};
CC -!- CATALYTIC ACTIVITY:
CC Reaction=Endonucleolytic cleavage to 5'-phosphomonoester.; EC=3.1.26.4;
CC -!- ACTIVITY REGULATION: Activated by host HSP70 and HSP40 in vitro to be
CC able to bind the epsilon loop of the pgRNA. Because deletion of the
CC RNase H region renders the protein partly chaperone-independent, the
CC chaperones may be needed indirectly to relieve occlusion of the RNA-
CC binding site by this domain.
CC -!- DOMAIN: Terminal protein domain (TP) is hepadnavirus-specific. Spacer
CC domain is highly variable and separates the TP and RT domains.
CC Polymerase/reverse-transcriptase domain (RT) and ribonuclease H domain
CC (RH) are similar to retrovirus reverse transcriptase/RNase H (By
CC similarity). {ECO:0000250}.
CC -!- DOMAIN: The polymerase/reverse transcriptase (RT) and ribonuclease H
CC (RH) domains are structured in five subdomains: finger, palm, thumb,
CC connection and RNase H. Within the palm subdomain, the 'primer grip'
CC region is thought to be involved in the positioning of the primer
CC terminus for accommodating the incoming nucleotide. The RH domain
CC stabilizes the association of RT with primer-template (By similarity).
CC {ECO:0000250}.
CC -!- SIMILARITY: Belongs to the hepadnaviridae P protein family.
CC {ECO:0000305}.
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; M22056; AAA45738.1; -; Genomic_DNA.
DR PIR; A30082; JDVLHH.
DR RefSeq; NP_040998.1; NC_001486.1.
DR PRIDE; P13846; -.
DR GeneID; 2703545; -.
DR KEGG; vg:2703545; -.
DR Proteomes; UP000008679; Genome.
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:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR GO; GO:0003964; F:RNA-directed DNA polymerase activity; IEA:UniProtKB-KW.
DR GO; GO:0004523; F:RNA-DNA hybrid ribonuclease activity; IEA:UniProtKB-EC.
DR GO; GO:0006260; P:DNA replication; IEA:UniProtKB-KW.
DR Gene3D; 3.30.70.270; -; 1.
DR InterPro; IPR043502; DNA/RNA_pol_sf.
DR InterPro; IPR001462; DNApol_viral_C.
DR InterPro; IPR000201; DNApol_viral_N.
DR InterPro; IPR043128; Rev_trsase/Diguanyl_cyclase.
DR InterPro; IPR000477; RT_dom.
DR Pfam; PF00336; DNA_pol_viral_C; 1.
DR Pfam; PF00242; DNA_pol_viral_N; 1.
DR Pfam; PF00078; RVT_1; 1.
DR SUPFAM; SSF56672; SSF56672; 1.
DR PROSITE; PS50878; RT_POL; 1.
PE 3: Inferred from homology;
KW DNA replication; DNA-binding; DNA-directed DNA polymerase; Endonuclease;
KW Hydrolase; Magnesium; Metal-binding; Multifunctional enzyme; Nuclease;
KW Nucleotidyltransferase; RNA-directed DNA polymerase; Transferase.
FT CHAIN 1..788
FT /note="Protein P"
FT /id="PRO_0000222332"
FT DOMAIN 376..565
FT /note="Reverse transcriptase"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00405"
FT REGION 1..200
FT /note="Terminal protein domain (TP)"
FT /evidence="ECO:0000250"
FT REGION 201..370
FT /note="Spacer"
FT /evidence="ECO:0000250"
FT REGION 230..381
FT /note="Disordered"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT REGION 656..788
FT /note="RnaseH domain (RH)"
FT /evidence="ECO:0000250"
FT COMPBIAS 340..355
FT /note="Polar residues"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT COMPBIAS 363..381
FT /note="Polar residues"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT BINDING 448
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_note="catalytic"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00405"
FT BINDING 515
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_note="catalytic"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00405"
FT BINDING 516
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_note="catalytic"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00405"
FT SITE 96
FT /note="Priming of reverse-transcription by covalently
FT linking the first nucleotide of the (-)DNA"
FT /evidence="ECO:0000250"
SQ SEQUENCE 788 AA; 90070 MW; FB44F38F75EADF44 CRC64;
MPQPLKQSLD QSRWLKEAEI KLRELENLVD SNLEDERLKP QLSMGEDVLS PEAGDPLHPN
VRAPLSHVIG ETRHDPPHLG NRDPARHKLG KLTGLYQMKG CEFNPHWKIP DISATNFSQE
IINECPSRNW KYLTPAKFWP KSISYLPVHS GVKPKYPEFQ QNHESLVNDY LNKLFEAGIL
YKRVSKHLVT FKGPYFTWEQ KHLVPQQHGA YSSKINDRQE SRRRRIITAT SSRKNDSSRI
FGAHNNGRKI SYHSTRDGSH RLSGRTSDPT SRGALAGGDS TPIGPGSTAA HPSTHHVDRR
RRQKGQGVLQ AISREPSETR RNGTTSHHRV ARCRTSSVED FTRRPFTQSK GAYPRQGTRG
TDPQGPKAHQ QEENGSYLRG NTSWPNRVTG RIFLVDKNSR NTEEARLVVD FSQFSKGKNA
MRFPKYWCPN LTTLRRILPV GMPRISLDLS QAFYHLPLAP ASSSRLAVSD GKQVYYFRKA
PMGVGLSPFL LHLFTTAIGA EIASRFNVWT FSYMDDFLLC HPSARHLNTI SHAVCTFLQE
FGIRINFDKM TPSPVTTIRF LGYEISKQHM KIEESRWNEL RTVIKKIKVG QWYDWKCIQR
FIGHLNFVLP FTKGNIEMLK PMYDACTHRV NFAFSSRYKI LLYKLTMGVC KLTLDPKVSL
PLPRVATDAT LTHGAISHIT GGSAVFTFSK VRDIHIQELL MVCLAKLMIK PRCILTDSTY
VCHRKFSKLP WHFAMYAKQL LTRLTLYYVP SKYNPADGPT RHKPPDWTAV TYTPLSKHIY
IPHRLCGL
