Mutations That Increase In Situ Priming Also Decrease Circularization for Duck Hepatitis B Virus
AUTOR(ES)
Loeb, Daniel D.
FONTE
American Society for Microbiology
RESUMO
The process of hepadnavirus reverse transcription involves two template switches during the synthesis of plus-strand DNA. The first involves translocation of the plus-strand primer from its site of generation, the 3′ end of minus-strand DNA, to the complementary sequence DR2, located near the 5′ end of the minus-strand DNA. Plus strands initiated from DR2 are extended to the 5′ end of the minus-strand DNA. At this point, the 3′ end of the minus strand becomes the template via the second template switch, a process called circularization. Elongation of circularized plus-strand DNA generates relaxed circular DNA. Although most virions contain relaxed circular DNA, some contain duplex linear DNA. Duplex linear genomes are synthesized when the plus-strand primer is used at the site of its generation, the 3′ end of the minus-strand template. This type of synthesis is called in situ priming. Although in situ priming is normally low, in some duck hepatitis B virus mutants this type of priming is elevated. For example, mutations within the 3′ end of the minus-strand DNA can lead to increased levels of in situ priming. We report here that these same mutations result in a second defect, a less efficient template switch that circularizes the genome. Although it is not clear how these mutations affect both steps in DNA replication, our findings suggest a commonality in the mechanism of initiation of plus-strand synthesis and the template switch that circularizes the genome.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=114372Documentos Relacionados
- Small DNA Hairpin Negatively Regulates In Situ Priming during Duck Hepatitis B Virus Reverse Transcription
- Mutations in Yeast Replication Proteins That Increase CAG/CTG Expansions Also Increase Repeat Fragility
- Selected mutations of the duck hepatitis B virus P gene RNase H domain affect both RNA packaging and priming of minus-strand DNA synthesis.
- Evidence that a capped oligoribonucleotide is the primer for duck hepatitis B virus plus-strand DNA synthesis.
- Recombinant Duck Interferon Gamma Inhibits Duck Hepatitis B Virus Replication in Primary Hepatocytes†
