DPOL_DHBV1
ID DPOL_DHBV1 Reviewed; 836 AA.
AC P03162;
DT 21-JUL-1986, integrated into UniProtKB/Swiss-Prot.
DT 01-OCT-1996, sequence version 2.
DT 03-AUG-2022, entry version 97.
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 Duck hepatitis B virus (strain United States/DHBV-16) (DHBV).
OC Viruses; Riboviria; Pararnavirae; Artverviricota; Revtraviricetes;
OC Blubervirales; Hepadnaviridae; Avihepadnavirus.
OX NCBI_TaxID=489543;
OH NCBI_TaxID=8835; Anas (ducks).
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX PubMed=6699938; DOI=10.1128/jvi.49.3.782-792.1984;
RA Mandart E., Kay A., Galibert F.;
RT "Nucleotide sequence of a cloned duck hepatitis B virus genome: comparison
RT with woodchuck and human hepatitis B virus sequences.";
RL J. Virol. 49:782-792(1984).
RN [2]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 794-836.
RX PubMed=6328037; DOI=10.1128/jvi.51.1.181-191.1984;
RA Molnar-Kimber K.L., Summers J.W., Mason W.S.;
RT "Mapping of the cohesive overlap of duck hepatitis B virus DNA and of the
RT site of initiation of reverse transcription.";
RL J. Virol. 51:181-191(1984).
RN [3]
RP ACTIVATION BY HOST HSC70 AND HSP40.
RX PubMed=12851401; DOI=10.1074/jbc.m301069200;
RA Beck J., Nassal M.;
RT "Efficient Hsp90-independent in vitro activation by Hsc70 and Hsp40 of duck
RT hepatitis B virus reverse transcriptase, an assumed Hsp90 client protein.";
RL J. Biol. Chem. 278:36128-36138(2003).
RN [4]
RP ACTIVATION BY HOST CHAPERONES.
RX PubMed=17913810; DOI=10.1128/jvi.01196-07;
RA Stahl M., Beck J., Nassal M.;
RT "Chaperones activate hepadnavirus reverse transcriptase by transiently
RT exposing a C-proximal region in the terminal protein domain that
RT contributes to epsilon RNA binding.";
RL J. Virol. 81:13354-13364(2007).
RN [5]
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; K01834; AAA45742.1; -; Genomic_DNA.
DR Proteomes; UP000180685; 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; IDA:UniProtKB.
DR GO; GO:0004523; F:RNA-DNA hybrid ribonuclease activity; IDA:UniProtKB.
DR GO; GO:0006260; P:DNA replication; IEA:UniProtKB-KW.
DR GO; GO:0090502; P:RNA phosphodiester bond hydrolysis, endonucleolytic; IDA:UniProtKB.
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..836
FT /note="Protein P"
FT /id="PRO_0000222327"
FT DOMAIN 424..613
FT /note="Reverse transcriptase"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00405"
FT REGION 51..250
FT /note="Terminal protein domain (TP)"
FT /evidence="ECO:0000250"
FT REGION 251..414
FT /note="Spacer"
FT /evidence="ECO:0000250"
FT REGION 263..417
FT /note="Disordered"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT REGION 415..703
FT /note="Polymerase/reverse transcriptase domain (RT)"
FT /evidence="ECO:0000250"
FT REGION 704..836
FT /note="RnaseH domain (RH)"
FT /evidence="ECO:0000250"
FT COMPBIAS 270..299
FT /note="Basic and acidic residues"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT COMPBIAS 335..349
FT /note="Basic and acidic residues"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT COMPBIAS 350..366
FT /note="Polar residues"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT COMPBIAS 373..416
FT /note="Polar residues"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT BINDING 496
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_note="catalytic"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00405"
FT BINDING 563
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_note="catalytic"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00405"
FT BINDING 564
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_note="catalytic"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00405"
FT SITE 146
FT /note="Priming of reverse-transcription by covalently
FT linking the first nucleotide of the (-)DNA"
FT /evidence="ECO:0000250"
SQ SEQUENCE 836 AA; 95276 MW; FFEB57CFF549A4F4 CRC64;
MQKLTRNHWI GLGDCFGGIT TVYCGEKLKL LTIFLVCVLG CQLLRNIEVE MPRPLKQSLD
QSRWLREAEK QLRVLENLVD SNLEEEKLKP QLSMGEDVQS PGKGEPLHPN VRAPLSHVVR
AATIDLPRLG NKLPARHHLG KLSGLYQMKG CTFNPEWKVP DISDTHFNLD VVNECPSRNW
KYLTPAKFWP KSISYFPVQV GVKPKYPDNV MQHESIVGKY LTRLYEAGIL YKRISKHLVT
FKGQPYNWEQ QHLVNQHHIY DGATSSKING RQTDRRRRNT VKPTCRKDDP KRDFDMVRQV
SNTRSRVRPC ANNGGDKHPP ESGSLACWGG KESRIIKSDS SRDSSAPVDS RGRPKSTRSF
SPLSRRKTTG NHHHSSVFPS SVEATTRGRS TPGKSVSPRD SSAIPVRTSG ASDKNSPLEE
ENVWYLRGNT SWPNRITGKL FLVDKNSRNT EEARLVVDFS QFSKGKNAMR FPRYWSPNLS
TLRRILPVGM PRISLDLSQA FYHLPLNPAS SSRLAVSDGQ RVYYFRKAPM GVGLSPFLLH
LFTTALGSEI SRRFNVWTFT YMDDFLLCHP NARHLNAISH AVCSFLQELG IRINFDKTTP
SPVNEIRFLG YQIDENFMKI EESRWKELRT VIKKIKVGEW YDWKCIQRFV GHLNFVLPFT
KGNIEMLKPM YAAITNQVNF SFSSSYRTLL YKLTMGVCKL RIKPKSSVPL PRVATDATPT
HGAISHITGG SAVFAFSKVR DIHVQELLMS CLAKIMIKPR CLLSDSTFVC HKRYQTLPWH
FAMLAKQLLK PIQLYFVPSK YNPADGPSRH KPPDWTAFPY TPLSKAIYIP HRLCGT
