Cell Host & Microbe
HIV-1 matrix-tRNA complex structure reveals basis for host control of Gag localization
Bou-Nader, C., Muecksch, F., Brown, J. B., Gordon, J. M., York, A., Peng, C., ... & Zhang, J.
HIV, Gag, matrix, tRNA, localization, plasma membrane, host-pathogen, interactions, RNA-protein interactions, assembly
The HIV-1 virion structural polyprotein, Gag, is directed to particle assembly sites at the plasma membrane by its N-terminal matrix (MA) domain. MA also binds to host tRNAs. To understand the molecular basis of MA-tRNA interaction and its potential function, we present a co-crystal structure of HIV-1 MA-tRNA(Lys3) complex. The structure reveals a specialized group of MA basic and aromatic residues preconfigured to recognize the distinctive structure of the tRNA elbow. Mutational, cross-linking, fluorescence, and NMR analyses show that the crystallographically defined interface drives MA-tRNA binding in solution and living cells. The structure indicates that MA is unlikely to bind tRNA and membrane simultaneously. Accordingly, single-amino-acid substitutions that abolish MA-tRNA binding caused striking redistribution of Gag to the plasma membrane and reduced HIV-1 replication. Thus, HIV-1 exploits host tRNAs to occlude a membrane localization signal and control the subcellular distribution of its major structural protein.