P17395 (DPOL_HBVB4) Reviewed, UniProtKB/Swiss-Prot
Last modified April 3, 2013. Version 62. History...
Names and origin
|Protein names||Recommended name:|
|Organism||Hepatitis B virus genotype B/C subtype adw (isolate Okinawa/pODW282/1998) (HBV-B) [Complete proteome]|
|Taxonomic identifier||10415 [NCBI]|
|Taxonomic lineage||Viruses › Retro-transcribing viruses › Hepadnaviridae › Orthohepadnavirus ›|
|Virus host||Homo sapiens (Human) [TaxID: 9606]|
Pan troglodytes (Chimpanzee) [TaxID: 9598]
|Sequence length||843 AA.|
|Protein existence||Inferred from homology|
General annotation (Comments)
Multifunctional enzyme that converts the viral RNA genome into dsDNA in viral cytoplasmic capsids. This enzyme displays a DNA polymerase activity that can copy either DNA or RNA templates, and a ribonuclease H (RNase H) activity that cleaves the RNA strand of RNA-DNA heteroduplexes in a partially processive 3'- to 5'-endonucleasic mode. Neo-synthesized pregenomic RNA (pgRNA) are encapsidated together with the P protein, and reverse-transcribed inside the nucleocapsid. Initiation of reverse-transcription occurs first by binding the epsilon loop on the pgRNA genome, and is initiated by protein priming, thereby the 5'-end of (-)DNA is covalently linked to P protein. Partial (+)DNA is synthesized from the (-)DNA template and generates the relaxed circular DNA (RC-DNA) genome. After budding and infection, the RC-DNA migrates in the nucleus, and is converted into a plasmid-like covalently closed circular DNA (cccDNA). The activity of P protein does not seem to be necessary for cccDNA generation, and is presumably released from (+)DNA by host nuclear DNA repair machinery By similarity.
Deoxynucleoside triphosphate + DNA(n) = diphosphate + DNA(n+1).
Endonucleolytic cleavage to 5'-phosphomonoester.
Activated by host HSP70 and HSP40 in vitro to be able to bind the epsilon loop of the pgRNA. Because deletion of the RNase H region renders the protein partly chaperone-independent, the chaperones may be needed indirectly to relieve occlusion of the RNA-binding site by this domain. Inhibited by several reverse-transcriptase inhibitors: Lamivudine, Adefovir and Entecavir By similarity.
Terminal protein domain (TP) is hepadnavirus-specific. Spacer domain is highly variable and separates the TP and RT domains. Polymerase/reverse-transcriptase domain (RT) and ribonuclease H domain (RH) are similar to retrovirus reverse transcriptase/RNase H By similarity.
The polymerase/reverse transcriptase (RT) and ribonuclease H (RH) domains are structured in five subdomains: finger, palm, thumb, connection and RNase H. Within the palm subdomain, the 'primer grip' region is thought to be involved in the positioning of the primer terminus for accommodating the incoming nucleotide. The RH domain stabilizes the association of RT with primer-template By similarity.
Hepadnaviral virions contain probably just one P protein molecule per particle By similarity.
Belongs to the hepadnaviridae P protein family.
Contains 1 reverse transcriptase domain.
Sequence annotation (Features)
|Feature key||Position(s)||Length||Description||Graphical view||Feature identifier|
|Chain||1 – 843||843||Protein P||PRO_0000222342|
|Domain||357 – 600||244||Reverse transcriptase|
|Region||1 – 177||177||Terminal protein domain (TP) By similarity|
|Region||178 – 346||169||Spacer By similarity|
|Region||347 – 690||344||Polymerase/reverse transcriptase domain (RT) By similarity|
|Region||691 – 843||153||RnaseH domain (RH) By similarity|
|Metal binding||429||1||Magnesium; catalytic By similarity|
|Metal binding||551||1||Magnesium; catalytic By similarity|
|Metal binding||552||1||Magnesium; catalytic By similarity|
|Site||63||1||Priming of reverse-transcription by covalently linking the first nucleotide of the (-)DNA By similarity|
|||"Typing hepatitis B virus by homology in nucleotide sequence: comparison of surface antigen subtypes."|
Okamoto H., Tsuda F., Sakugawa H., Sastrosoewignjo R.I., Imai M., Miyakawa Y., Mayumi M.
J. Gen. Virol. 69:2575-2583(1988) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA].
|||"Hepatitis B virus replication."|
Beck J., Nassal M.
World J. Gastroenterol. 13:48-64(2007) [PubMed] [Europe PMC] [Abstract]
Cited for: REVIEW.
Hepatitis virus B database
|D00330 Genomic DNA. No translation available.|
|PIR||JDVLJ2. E28925. |
3D structure databases
Protocols and materials databases
Family and domain databases
|InterPro||IPR001462. DNApol_viral_C. |
|Pfam||PF00336. DNA_pol_viral_C. 1 hit. |
PF00242. DNA_pol_viral_N. 1 hit.
PF00078. RVT_1. 1 hit.
|PROSITE||PS50878. RT_POL. 1 hit. |
|Accession||Primary (citable) accession number: P17395|
|Entry status||Reviewed (UniProtKB/Swiss-Prot)|
|Annotation program||Viral Protein Annotation Program|
Index of protein domains and families