The accuracy of reverse transcriptase from HIV-1.
A study was conducted to determine the fidelity of DNA synthesis catalyzed in vitro by the reverse transcriptase from a human immunodeficiency virus type 1 (HIV-1). Like other retroviral reverse transcriptases, the HIV-1 enzyme does not correct errors by exonucleolytic proofreading. Measurements with M13mp2-based fidelity assays indicated that the HIV-1 enzyme, isolated either from virus particles or from Escherichia coli cells infected with a plasmid expressing the cloned gene, was exceptionally inaccurate, having an average error rate per detectable nucleotide incorporated of 1/1700. It was, in fact, the least accurate reverse transcriptase described to date, one-tenth as accurate as the polymerases isolated from avian myeloblastosis or murine leukemia viruses, which have average error rates of approximately 1/17,000 and approximately 1/30,000, respectively. DNA sequence analyses of mutations generated by HIV-1 polymerase showed that base substitution, addition, and deletion errors were all produced. Certain template positions were mutational hotspots where the error rate could be as high as 1 per 70 polymerized nucleotides. The data are consistent with the notion that the exceptional diversity of the HIV-1 genome results from error-prone reverse transcription.
Roberts
J D
JD
Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709.
Bebenek
K
K
Kunkel
T A
TA
D009189:Avian Myeloblastosis Virus / Q000201:enzymology; D004247:DNA / Q000096:biosynthesis*; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000201:enzymology; D005092:Exonucleases / Q000378:metabolism; D006678:HIV / Q000201:enzymology*; D008979:Moloney murine leukemia virus / Q000201:enzymology; D009154:Mutation; D009711:Nucleotides / Q000378:metabolism; D012194:RNA-Directed DNA Polymerase / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism
D009711:Nucleotides; D011994:Recombinant Proteins; D004247:DNA; D012194:RNA-Directed DNA Polymerase; D004259:DNA-Directed DNA Polymerase; D005092:Exonucleases