Motion of Knots in DNA Stretched by Elongational Fields

Knots in DNA occur in biological systems, serve as a model system for polymer entanglement, and affect the efficacy of modern genomics technologies. We study the motion of complex knots in DNA by stretching molecules with a divergent electric field that provides an elongational force. We demonstrate...

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Bibliographic Details
Main Authors: Klotz, Alexander, Soh, Beatrice W, Doyle, Patrick S
Other Authors: Massachusetts Institute of Technology. Department of Chemical Engineering
Format: Article
Language:English
Published: American Physical Society 2018
Online Access:http://hdl.handle.net/1721.1/115296
https://orcid.org/0000-0001-8399-5995
https://orcid.org/0000-0003-2147-9172
Description
Summary:Knots in DNA occur in biological systems, serve as a model system for polymer entanglement, and affect the efficacy of modern genomics technologies. We study the motion of complex knots in DNA by stretching molecules with a divergent electric field that provides an elongational force. We demonstrate that the motion of knots is nonisotropic and driven towards the closest end of the molecule. We show for the first time experimentally that knots can go from a mobile to a jammed state by varying an applied strain rate, and that this jamming is reversible. We measure the mobility of knots as a function of strain rate, demonstrating the conditions under which knots can be driven towards the ends of the molecule and untied.