Initiation of minus (-) strand DNA synthesis was examined on templates containing R, U5, and primer-binding site regions of the human immunodeficiency virus type 1 (HIV-1), feline immunodeficiency virus (FIV), and equine infectious anemia virus (EIAV) genomic RNA. DNA synthesis was initiated from (i) an oligoribonucleotide complementary to the primer-binding sites, (ii) synthetic tRNALys 3, and (iii) natural tRNALys 3, by the reverse transcriptases of HIV-1, FIV, EIAV, simian immunodeficiency virus, HIV type 2 (HIV-2), Moloney murine leukemia virus, and avian myeloblastosis virus. All enzymes used an oligonucleotide on wild-type HIV-1 RNA, whereas only a limited number initiated (-) strand DNA synthesis from either tRNALys 3. In contrast, all enzymes supported efficient tRNALys 3-primed (-) strand DNA synthesis on the genomes of FIV and EIAV. This may be in part attributable to the observation that the U5-inverted repeat stem-loop of the EIAV and FIV genomes lacks an A-rich loop shown with HIV-1 to interact with the U-rich tRNA anticodon loop. Deletion of this loop in HIV-1 RNA, or disrupting a critical loop-loop complex by tRNALys 3 extended by 9 nt, restored synthesis of HIV-1 (-) strand DNA from primer tRNALys 3 by all enzymes. Thus, divergent evolution of lentiviruses may have resulted in different mechanisms to use the same host tRNA for initiation of reverse transcription.
|Original language||English (US)|
|Number of pages||6|
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|State||Published - Sep 17 1996|
- HIV-1 reverse transcription
- Retroviral replication
ASJC Scopus subject areas