title: Dual role for motif 1 residues of human lysyl-tRNA synthetase in dimerization and packaging into HIV-1.
abstract: The primer for reverse transcription in human immunodeficiency virus type 1, human tRNA(Lys,3), is selectively packaged into the virion along with tRNA(Lys1,2). Human lysyl-tRNA synthetase (hLysRS), the only cellular factor known to interact specifically with all three tRNA(Lys) isoacceptors, is also selectively packaged into HIV-1. We have previously defined a tRNA(Lys) packaging complex that includes the tRNA(Lys) isoacceptors, LysRS, HIV-1 Gag, GagPol, and viral RNA. Numerous studies support the hypothesis that during tRNA(Lys) packaging, a Gag·GagPol complex interacts with a tRNA(Lys)·LysRS complex, with Gag interacting specifically with the catalytic domain of LysRS, and GagPol interacting with both Gag and tRNA(Lys). In this work, we have identified residues along one face of the motif 1 dimerization helix (H7) of hLysRS that are critical for packaging of the synthetase into virions. Mutation of these residues affects binding to Gag in vitro, as well as the oligomerization state and aminoacylation activity of the synthetase. Taken together, these data suggest that H7 of LysRS has a dual function. In its canonical role it maintains the synthetase dimer interface, whereas in its function in tRNA primer recruitment, it bridges interactions with HIV-1 Gag.
authors.affiliation: Department of Chemistry and Biochemistry, Ohio State Biochemistry Program, Center for RNA Biology, The Ohio State University, Columbus, Ohio 43210, USA.
authors.forename: Varun
authors.initials: V
authors.lastname: Dewan
authors.forename: Min
authors.initials: M
authors.lastname: Wei
authors.forename: Lawrence
authors.initials: L
authors.lastname: Kleiman
authors.forename: Karin
authors.initials: K
authors.lastname: Musier-Forsyth
mesh_terms: D020816:Amino Acid Motifs; D020134:Catalytic Domain; D015685:Fusion Proteins, gag-pol / Q000235:genetics / Q000378:metabolism; D057809:HEK293 Cells; D015658:HIV Infections / Q000235:genetics / Q000378:metabolism*; D015497:HIV-1 / Q000502:physiology*; D006801:Humans; D008250:Lysine-tRNA Ligase / Q000235:genetics / Q000378:metabolism*; D020125:Mutation, Missense; D055503:Protein Multimerization; D012367:RNA, Viral / Q000235:genetics / Q000378:metabolism; D019065:Virus Assembly / Q000502:physiology*; D054301:gag Gene Products, Human Immunodeficiency Virus / Q000235:genetics / Q000378:metabolism
chemical_list: D015685:Fusion Proteins, gag-pol; D012367:RNA, Viral; D054301:gag Gene Products, Human Immunodeficiency Virus; D008250:Lysine-tRNA Ligase