The physics of target-site search and DNA supercoiling in the cell

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Abstract/Contents

Abstract
Protein-DNA interactions within the confines of the crowded cellular space control critical biological processes such as genome regulation, replication, and compaction. In turn, protein activity on the genome is susceptible to the structure and dynamics of the DNA itself, a complex relationship whose study falls within the realm of polymer physics. Using analytical theory and numerical simulations, we present a systematic study of the relationship between DNA structure and dynamics and cellular processes mediated by DNA-binding proteins, in particular those involving a search for a target-site on the chromosome. We build a theoretical description of the transport of DNA-binding proteins along linear DNA modeled as a wormlike chain and delineate the resulting dynamic strategies employed by the cell in order to maximize translocation speed and efficiency. We extend this model to address the otherwise imperceptible molecular events present during effective protein diffusion along a stretched DNA strand during single-molecule experiments. In an effort to address the genome's higher-order structural effects, we explore the structure and dynamics of supercoiled DNA both as a free molecule in solution and under confinement in the cell, as in the case of Caulobacter crescentus. Our investigation of supercoiled DNA in confinement highlights dynamic consequences of vital importance to the cell's genome regulatory strategies. Finally, we synthesize our study of DNA-binding protein transport with our investigation of supercoiling dynamics to address the effect of DNA superstructure on the target-site search process, and we identify the search enhancement wrought by supercoiling of the chromosome.

Description

Type of resource text
Form electronic; electronic resource; remote
Extent 1 online resource.
Publication date 2012
Issuance monographic
Language English

Creators/Contributors

Associated with Diaz de la Rosa, Mario Alfonso
Associated with Stanford University, Department of Chemical Engineering
Primary advisor Spakowitz, Andrew James
Thesis advisor Spakowitz, Andrew James
Thesis advisor Bryant, Zev David
Thesis advisor Shaqfeh, Eric S. G. (Eric Stefan Garrido)
Advisor Bryant, Zev David
Advisor Shaqfeh, Eric S. G. (Eric Stefan Garrido)

Subjects

Genre Theses

Bibliographic information

Statement of responsibility Mario Alfonso Díaz de la Rosa.
Note Submitted to the Department of Chemical Engineering.
Thesis Thesis (Ph.D.)--Stanford University, 2012.
Location electronic resource

Access conditions

Copyright
© 2012 by Mario Alfonso Diaz de la Rosa
License
This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).

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