PRIMER SELECTION BY HIV-1 REVERSE-TRANSCRIPTASE ON RNA-TRNA(3)(LYS) AND DNA-TRNA(3)(LYS) HYBRIDS

During reverse transcription of the genomic RNA of human immunodeficie ncy virus type 1 (HIV-1) into double-stranded DNA, reverse transcripta se (RT) must accommodate RNA-RNA, DNA-RNA, RNA-DNA and DNA-DNA hybrids as primer-template. In this study, we examined extension of RNA-tRNA( 3)(Lys) and DNA-tRNA(3)(Lys) complexes by HIV-1 RT. When the 3' end of tRNA(3)(Lys) is annealed to oligoribonucleotides, tRNA(3)(Lys), but no t the complementary RNAs, is extended by HIV-1 RT, indicating that tRN A(3)(Lys) is efficiently used as primer and RNA as template. An opposi te primer usage is observed when tRNA(3)(Lys) is annealed to complemen tary oligodeoxyribonucleotides. In this case, the oligodeoxyribonucleo tides are efficiently used as primer and tRNA(3)(Lys) as template. Thi s result indicates that the nature of nucleic acid bound to tRNA(3)(Ly s) determines which strand of the RNA-tRNA(3)(Lys) and DNA-tRNA(3)(Lys ) hybrids is extended by HIV-1 RT. When an oligoribonucleotide is anne aled to an unmodified transcript of tRNA(3)(Lys), both nucleic acids a re extended by HIV-1 RT, indicating that specific selection of tRNA(3) (Lys) as primer requires the post-transcriptional modifications of tRN A(3)(Lys). (C) 1996 Academic Press Limited.