Premature strand transfer by the HIV-1 reverse transcriptase during strong-stop DNA synthesis.
Reverse transcription of retroviral genomes starts near the 5' end of the viral RNA by use of an associated tRNA primer. According to the current model of reverse transcription, the initial cDNA product, termed minus-strand strong-stop DNA, 'jumps' to a repeated sequence (R region) at the 3' end of the RNA template. The human retroviruses have relatively long R regions (97-247 nucleotides) when compared to murine and avian viruses (16-68 nucleotides). This suggests that the full complement of the R region is not required for strand transfer and that partial cDNA copies of the 5' R can prematurely jump to the 3' R. To test this hypothesis, we generated mutants of the human immunodeficiency virus with R region changes and analyzed whether 5' or 3' R sequences were inherited by the progeny. We found that in most cases, 5' R-encoded sequences are dominant, which is consistent with the model of reverse transcription. Using a selection protocol, however, we were also able to identify progeny viruses with R sequences derived from the original 3' R element. These results suggest that partial strong stop cDNAs can be transferred with R region homologies much shorter than 97 nucleotides.
Klaver
B
B
University of Amsterdam, Department of Virology, The Netherlands.
Berkhout
B
B
D001483:Base Sequence; D002460:Cell Line; D004279:DNA, Viral / Q000096:biosynthesis*; D016325:HIV Long Terminal Repeat; D054303:HIV Reverse Transcriptase; D015497:HIV-1 / Q000235:genetics*; D008969:Molecular Sequence Data; D009154:Mutation; D012367:RNA, Viral / Q000235:genetics*; D012194:RNA-Directed DNA Polymerase / Q000378:metabolism*; D011995:Recombination, Genetic; D013698:Templates, Genetic; D014158:Transcription, Genetic / Q000502:physiology*
D004279:DNA, Viral; D012367:RNA, Viral; D054303:HIV Reverse Transcriptase; D012194:RNA-Directed DNA Polymerase