Poster abstracts

Poster number 17 submitted by Varun Dewan

Mapping the Interaction between Human Lysyl-tRNA Synthetase and HIV-1 Capsid

Varun Dewan (Chemistry and Biochemistry, The Ohio State University, Columbus, OH), Michael Ignatov (Chemistry, The Ohio State University, Columbus, OH), Wei Wang (Chemistry, The Ohio State University, Columbus, OH), Oscar Torres (Chemistry, The Ohio State University, Columbus, OH), Dennis Bong (Chemistry, The Ohio State University, Columbus, OH), Lawrence Kleiman (Lady Davis Institute for Medical Research and McGill AIDS Centre, Jewish General Hospital, Montreal, Quebec, Canada)

Abstract:
Human tRNA^Lys3 is used as the primer for HIV-1 reverse transcription. HIV-1 Gag and host cell lysyl-tRNA synthetase (LysRS) are both required for specific packaging of tRNA^Lys into virions and these two proteins have been shown to interact in vitro. The capsid (CA) domain of Gag binds to LysRS with a similar affinity as full-length Gag. We have characterized the interaction between HIV-1 CA and human LysRS using truncation constructs, point mutants, and biophysical studies including mass spectrometry footprinting. The interaction involves helix 7 within the motif 1 dimerization domain of LysRS and the helix 4 region within the C-terminal domain of CA. Residues critical for maintaining this interaction in vitro and for packaging of LysRS in vivo have been identified. Synthetic peptides derived from the putative interaction helices bind to their respective protein partners and stabilized “stapled” peptides are currently being prepared and tested. Ongoing work is aimed at using these peptides as tools to identify molecules that disrupt this protein-protein interaction.

Keywords: LysRS packaging, LysRS-CA interactions