Peptidyl-tRNA are generated from stalled ribosomes. Peptidyl-tRNA hydrolase, Pth, is the enzyme essential for the removal of bound peptides from tRNA molecules. Peptidyl-tRNAs are toxic to cells and without Pth "recycling", the cell dies because of impaired translation initiation and slowed protein synthesis due to specific tRNA starvation. The essential activity of Pth makes it a hight value drug target. Disrupting Pth activity leads to bacterial death and since no direct Pth homolog is found in humans, few side effects are expected from inhibitors. In collaboration, we are looking at the high resolution structure of the Pth:peptidyl-tRNA complex using a combination of NMR and small-angle neutron scattering. Also, we are screening tropical cloudforest extracts, expected to contain phytochemicals with novel structural motifs and novel mechanisms of bioactivity, for Pth inhibitors. Numerous extracts have been identified with anti-Pth activity and identification of the active compounds is in progress.
X-ray Diffraction Structures
Overlay of P. aeruginosa Pth1 (blue) and S. typhimurium Pth1 (red) onto E. coli Pth1 (white).
NMR Resonance Assignment
||15N-TROSY HSQC of Pth (red) with15N-phenylalanine residue specifically labeled resonances offset (blue).
||Northern blot of peptidyl-tRNA migration.
Inhibitor Indentification (coming soon)
Small Angle Neutron Scattering (coming soon)