Soft Matter and Complex Systems Seminar
sala 1.40, ul. Pasteura 5
2020-10-30 (09:30) 
Radost Waszkiewicz (IFT UW)
Dynamics and shape of DNA minicircles
In most organisms, DNA is in an underwound or overwound state, however, typical experiments involve short linear segments of DNA which have relaxed twist.
Closing the DNA in circular loops, allows the twist to be maintained during an experiment to study the effect of under/overwinding on its properties, but changing DNA segment topology changes all the relevant forces: elastic, hydrodynamic and Brownian. Such loops are already being synthesised in laboratories but suitable theoretical description is needed to interpret experimental results.
To this aim, we consider simplified models of DNA loops. Using resistive force theory we are able to understand the influence of drag on the shape of minicircles. Furthermore, using Timoshenko beam theory, we can explore the influence of the imposed twist on shape and Brownian fluctuations. Our results indicate that, for small enough minicircles, it is the elastic forces that lead to multiplicity of observed shape configurations.
The seminar will be conducted on Zoom
https://zoom.us/j/92987083349?pwd=YTZLSFVWUnJzdE4xS1drR3dqMVFDdz09
Meeting ID: 929 8708 3349
Passcode: a8QhyS
Closing the DNA in circular loops, allows the twist to be maintained during an experiment to study the effect of under/overwinding on its properties, but changing DNA segment topology changes all the relevant forces: elastic, hydrodynamic and Brownian. Such loops are already being synthesised in laboratories but suitable theoretical description is needed to interpret experimental results.
To this aim, we consider simplified models of DNA loops. Using resistive force theory we are able to understand the influence of drag on the shape of minicircles. Furthermore, using Timoshenko beam theory, we can explore the influence of the imposed twist on shape and Brownian fluctuations. Our results indicate that, for small enough minicircles, it is the elastic forces that lead to multiplicity of observed shape configurations.
The seminar will be conducted on Zoom
https://zoom.us/j/92987083349?pwd=YTZLSFVWUnJzdE4xS1drR3dqMVFDdz09
Meeting ID: 929 8708 3349
Passcode: a8QhyS