Site-specific RNA binding by a hepatitis B virus reverse transcriptase initiates two distinct reactions: RNA packaging and DNA synthesis.

AUTOR(ES)

Pollack, J R

RESUMO

Hepatitis B viruses encode a polymerase (P) protein with key roles in both reverse transcription and genomic RNA encapsidation. Genetic analysis of cis-acting signals required for viral replication implicates an RNA stem-loop structure in both RNA packaging and the initiation of reverse transcription, a process in which P protein also serves as the primer. We now show that duck hepatitis B virus (DHBV) polymerase binds specifically and with high affinity to this RNA stem-loop structure. Mutational analysis indicates that all mutations in the RNA target that inhibit the P protein-RNA interaction inhibit both in vivo RNA packaging and in vitro DNA priming to comparable extents. However, certain mutations in the loop region of the RNA have minimal impact on P protein-RNA binding but are nonetheless severely defective for packaging and DNA synthesis. Thus, P protein-RNA complex formation is necessary but not sufficient to initiate these activities. In addition, examination of RNA binding by truncated P proteins indicates that the C terminus of the polymerase, although required for RNA encapsidation in vivo, is dispensable for RNA binding and DNA priming.

Documentos Relacionados

• Site-specific deletion in cauliflower mosaic virus DNA: possible involvement of RNA splicing and reverse transcription
• Site-specific carcinogen binding to DNA.
• Site-specific crosslinking of 4-thiouridine-modified human tRNA(3Lys) to reverse transcriptase from human immunodeficiency virus type I.
• Template switching by reverse transcriptase during DNA synthesis.
• Efficient Site-Specific Nonribozyme Opening of Hepatitis Delta Virus Genomic RNA in Infected Livers