Mechanism of RNA primer removal by the RNase H activity of avian myeloblastosis virus reverse transcriptase.
AUTOR(ES)
Champoux, J J
RESUMO
The single-stranded DNA containing the Moloney murine leukemia virus origin for plus-strand synthesis was cloned in M13mp2 and used as a template for avian myeloblastosis virus reverse transcriptase in the presence of Moloney RNA which had been treated with pancreatic RNase A. The RNA pieces containing the polypurine stretch near the plus-strand origin were processed, presumably by RNase H, to generate primers for DNA synthesis which initiated both at the correct origin site and at one nucleotide downstream from the correct site. Approximately 50% of the labeled DNA fragments synthesized under these conditions retained the priming RNA on their 5' ends. When the isolated fragments were hybridized back to the template DNA and again treated with the reverse transcriptase, all of the RNA was removed from the labeled DNA. By using 5'-end-labeled pancreatic RNase A-resistant fragments, it was possible to show that the RNA primers were removed intact. It appears from these results that the RNase H activity associated with the enzyme shows a preference for cutting at the junction between the RNA and DNA moieties of such complexes and therefore is ideally suited for removing RNA primers.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=255525Documentos Relacionados
- Mechanism of interaction of avian myeloblastosis virus reverse transcriptase with avian myeloblastosis virus RNA.
- RNA primer used in synthesis of anticomplementary DNA by reverse transcriptase of avian myeloblastosis virus.
- Reverse transcriptase of RNA tumor viruses. V. In vitro proteolysis of reverse transcriptase from avian myeloblastosis virus and isolation of a polypeptide manifesting only RNase H activity.
- Incomplete removal of the RNA primer for minus-strand DNA synthesis by human immunodeficiency virus type 1 reverse transcriptase.
- Structural features required for the binding of tRNATrp to avian myeloblastosis virus reverse transcriptase.