The maintenance of intact genetic information, as well as the deployment of transcription for specific sets of genes, critically rely on a family of proteins interacting with DNA and recognizing specific sequences or features. The mechanisms by which these proteins search for target DNA are the subject of intense investigations employing a variety of methods in biology. A large interest in these processes stems from the faster-than-diffusion association rates, explained in current models by a combination of 3D and 1D diffusion. Here, we describe the combination of optical tweezers and single molecule fluorescence detection for the study of protein-DNA interaction. The method offers the opportunity of investigating interactions occurring in solution (thus avoiding problems due to closeby surfaces as in other single molecule methods), controlling the DNA extension and tracking interaction dynamics as a function of both mechanical parameters and DNA sequence.

Date Published: 12 September 2013
PDF: 6 pages
Proc. SPIE 8810, Optical Trapping and Optical Micromanipulation X, 88102O (12 September 2013); doi: 10.1117/12.2023596

Published in SPIE Proceedings Vol. 8810:
Optical Trapping and Optical Micromanipulation X
Kishan Dholakia; Gabriel C. Spalding, Editor(s)