Femtonewton Forces Can Control Protein-Meditated DNA Looping
Biomolecules
2010-01-05 v1
Abstract
We show that minuscule entropic forces, on the order of 100 fN, can prevent the formation of DNA loops--a ubiquitous means of regulating the expression of genes. We observe a tenfold decrease in the rate of LacI-mediated DNA loop formation when a tension of 200 fN is applied to the substrate DNA, biasing the thermal fluctuations that drive loop formation and breakdown events. Conversely, once looped, the DNA-protein complex is insensitive to applied force. Our measurements are in excellent agreement with a simple polymer model of loop formation in DNA, and show that an anti-parallel topology is the preferred LacI-DNA loop conformation for a generic loop-forming construct.
Cite
@article{arxiv.1001.0546,
title = {Femtonewton Forces Can Control Protein-Meditated DNA Looping},
author = {Yih-Fan Chen and J. N. Milstein and J. -C. Meiners},
journal= {arXiv preprint arXiv:1001.0546},
year = {2010}
}