The duck hepatitis B virus P-gene codes for protein strongly associated with the 5'-end of the viral DNA minus strand.
A number of antisera, elicited against different segments of the duck hepatitis B virus (DHBV) P-gene translation product, were used to immunoprecipitate the protein that is covalently bound to the 5'-end of the DHBV DNA minus strand. For monitoring purposes, a small DNA minus-strand fragment, carrying this protein, was radioactively labeled. All of the P-specific antisera specifically immunoprecipitated this DNA fragment demonstrating that the protein species attached to the immunoprecipitated DNA fragment were products of the DHBV P-gene. The electrophoretic behavior, in SDS gels, of the DNA minus-strand fragment-protein complex indicated that it was present mostly in the form of aggregates. However, a small fraction consisted of DNA minus-strand fragments carrying P-gene proteins, encoded solely within the 5'-region of the P-gene. This indicated that different P-gene proteins, presumably covalently bound at a common region and subsequently processed, were bound to the 5'-end of the DHBV DNA minus strand. The DHBV P-gene presumably codes for the virus-associated reverse transcriptase and DNA polymerase activities. Using the P-gene-specific antisera, it was not possible to detect putative P-gene-coded polymerase proteins in a free form, i.e., not bound to viral DNA. This may be due to insufficient sensitivity or to the polymerase protein(s) being heterogeneous and/or aggregated. In addition, it is possible that the genome-bound protein itself may have polymerase activity.
Bosch
V
V
Zentrum für Molekulare Biologie, Universität Heidelberg, Federal Republic of Germany.
Bartenschlager
R
R
Radziwill
G
G
Schaller
H
H
D000818:Animals; D003001:Cloning, Molecular; D004279:DNA, Viral / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics*; D004372:Ducks / Q000382:microbiology; D005814:Genes, Viral; D006515:Hepatitis B virus / Q000235:genetics*; D008970:Molecular Weight; D011233:Precipitin Tests; D011993:Recombinant Fusion Proteins / Q000276:immunology; D014764:Viral Proteins / Q000235:genetics* / Q000276:immunology
D004279:DNA, Viral; D004268:DNA-Binding Proteins; D011993:Recombinant Fusion Proteins; D014764:Viral Proteins