lmmol · Proteins

Protein P

UniProt P03159 Organism Hepatitis B virus genotype A2 subtype adw2 (strain Rutter 1979) Gene P EC 2.7.7.7, 2.7.7.49, 3.1.26.4

Also known as: P

Function

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.

Classification

Family (Pfam)
PF00336 DNA_pol_viral_C, PF00242 DNA_pol_viral_N, PF00078 RVT_1
InterPro
DNA/RNA_pol_sf, DNApol_viral_C, DNApol_viral_N, HBV_DPOL, Rev_trsase/Diguanyl_cyclase, RT_dom, Viral_Replic_Matur_Polypro
Functional cluster
Tubulins & Mitochondrial Metabolic Enzymes

Gene Ontology · 7

Drugs targeting this protein · 2

Related proteins · sequence + function similarity

Co-cited proteins · studied together in the literature

Literature · 5 cited papers

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