DynaTweezers: Elucidating the Molecular Mechanisms of Bacterial Gene Silencing using Tethered Particles and Optical Tweezing

Objetivo

Antimicrobial-resistance is a growing concern in modern medicine. The spread of antibiotic resistant genes, both within bacteria species and between species, is greatly accelerated by horizontal gene-transfer. In intestinal bacteria, a major pool of antimicrobial resistance, the impact of foreign acquired DNA is modulated by H-NS proteins that recognize and silence its expression. I propose to investigate the molecular mechanism of gene silencing by H-NS and related co-regulatory proteins at a single molecular level. With the understanding of the underlying mechanisms, we may enable the development of medicines that revert or suppress the expression of antimicrobial-resistant genes.

I plan to investigate the silencing mechanism of H-NS using a combination of dynamic Tethered Particle Motion and axial Optical Tweezers. These techniques allow me to characterize the repeated transcription of individual DNA strands in high detail under a variety of external conditions and under applied forces. Using these techniques, I can systematically study how transcription is affected by stalling of the transcription complex, loop formation and promotor occlusion. My experience in biophysical measurement techniques, in combination with the high performance optical tweezer expertise and an established network of H-NS research in Toronto enable the proposed research in a unique and powerful way.