Combining mutations in HIV-1 reverse transcriptase with mutations in the HIV-1 polypurine tract affects RNase H cleavages involved in PPT utilization.
The RNase H cleavages that generate and remove the polypurine tract (PPT) primer during retroviral reverse transcription must be specific to generate linear viral DNAs that are suitable substrates for the viral integrase. To determine if specific contacts between reverse transcriptase (RT) and the PPT are a critical factor in determining the cleavage specificity of RNase H, we made HIV-1 viruses containing mutations in RT and the PPT at the locations of critical contacts between the protein and the nucleic acid. The effects on titer and RNase H cleavage suggest that combining mutations in RT with mutations in the PPT affect the structure of the protein of the RT/nucleic acid complex in ways that affect the specificity and the rate of PPT cleavage. In contrast, the mutations in the PPT (alone) and RT (alone) affect the specificity of PPT cleavage but have much less effect on the overall rate of cleavage.
HIV Drug Resistance Program, NCI-Frederick, MD 21702-1201, USA.
Mary Jane
MJ
McWilliams
John G
JG
Julias
Stefan G
SG
Sarafianos
W Gregory
WG
Alvord
Eddy
E
Arnold
Stephen H
SH
Hughes
D001483:Base Sequence; D002460:Cell Line; D004279:DNA, Viral / Q000096:biosynthesis / Q000235:genetics; D054303:HIV Reverse Transcriptase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D015497:HIV-1 / Q000235:genetics* / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D046911:Macromolecular Substances; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D012367:RNA, Viral / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D016914:Ribonuclease H / Q000378:metabolism*; D013379:Substrate Specificity; D014162:Transfection
D004279:DNA, Viral; D046911:Macromolecular Substances; D012367:RNA, Viral; D054303:HIV Reverse Transcriptase; D016914:Ribonuclease H