The connection domain in reverse transcriptase facilitates the in vivo annealing of tRNA(Lys3 )to HIV-1 genomic RNA

The primer tRNA for reverse transcription in HIV-1, tRNA(Lys3), is selectively packaged into the virus during its assembly, and annealed to the viral genomic RNA. The ribonucleoprotein complex that is involved in the packaging and annealing of tRNA(Lys )into HIV-1 consists of Gag, GagPol, tRNA(Lys), lysyl-tRNA synthetase (LysRS), and viral genomic RNA. Gag targets tRNA(Lys )for viral packaging through Gag's interaction with LysRS, a tRNA(Lys)-binding protein, while reverse transcriptase (RT) sequences within GagPol (the thumb domain) bind to tRNA(Lys). The further annealing of tRNA(Lys3 )to viral RNA requires nucleocapsid (NC) sequences in Gag, but not the NC sequences GagPol. In this report, we further show that while the RT connection domain in GagPol is not required for tRNA(Lys3 )packaging into the virus, it is required for tRNA(Lys3 )annealing to the viral RNA genome.