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arXiv · 1002.3809

Protein-mediated DNA Loop Formation and Breakdown in a Fluctuating Environment

Yih-Fan Chen·J. N. Milstein·Jens-Christian Meiners
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Abstract

Living cells provide a fluctuating, out-of-equilibrium environment in which genes must coordinate cellular function. DNA looping, which is a common means of regulating transcription, is very much a stochastic process; the loops arise from the thermal motion of the DNA and other fluctuations of the cellular environment. We present single-molecule measurements of DNA loop formation and breakdown when an artificial fluctuating force, applied to mimic a fluctuating cellular environment, is imposed on the DNA. We show that loop formation is greatly enhanced in the presence of noise of only a fraction of $k_B T$, yet find that hypothetical regulatory schemes that employ mechanical tension in the DNA--as a sensitive switch to control transcription--can be surprisingly robust due to a fortuitous cancellation of noise effects.

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Yih-Fan Chen, J. N. Milstein, Jens-Christian Meiners. 2010-04-21. Protein-mediated DNA Loop Formation and Breakdown in a Fluctuating Environment. https://doi.org/10.1103/physrevlett.104.258103

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