Exploring the Mechanics and Dynamics of Gene Silencing Proteins

Abstract

Horizontal gene transfer provides great advantages to micro-organisms like bacteria in building up resistance to antibiotics and extending the range of phenotypes. However this process needs to be tightly regulated. That because inappropriate expression of newly acquired genes will lead to a waste of resources and often cell death. The histone-like nucleoid structuring (H-NS) protein, plays a key role in indentifying and selectively repressing foreign genes in bacteria. DNA-protein interactions with H-NS and its cofactor Hha were studied by tethered particle motion (TPM), optical tweezers and atomic force microscopy (AFM). Our results show that these proteins greatly alter the mechanical characteristics of the DNA and that the protein-DNA interactions can be reorganized after applying a force. We also present a new approach to studying protein-DNA interactions with AFM.