Incorporation of Lysyl-tRNA synthetase into human immunodeficiency virus type 1

During human immunodeficiency virus type 1 (HIV-1) assembly, tRNA(Lys) isoacceptors are selectively incorporated into virions and tRNA(3)(Lys) is used as the primer for reverse transcription. We show herein that the tRNA(Lys)-binding protein, lysyl-tRNA synthetase (LysRS), is also selectively packaged into HIV-1. The viral precursor protein Pr55(gag) alone will package LysRS into Pr55(gag) particles, independently of tRNA(Lys). With the additional presence of the viral precursor protein Pr160(gag-pol), tRNA(Lys) and LysRS are both packaged into the particle. While the predominant cytoplasmic LysRS has an apparent M-r of 70,000, viral LysRS associated with tRNA(Lys) packaging is shorter, with an apparent M-r of 63,000. The truncation occurs independently of viral protease and might be required to facilitate interactions involved in the selective packaging and genomic placement of primer tRNA(3)(Lys).