DNA mechanical properties
DNA bending and torsional elasticity directly affect most, if not all, genome functions by altering the affinity of proteins for their DNA binding sites, the likelihood of protein-protein or protein-DNA interactions, the activity of DNA enzymes and DNA/chromatin packaging. We study parameters that affect DNA elasticity such as polycations, base pairing, bending and coating proteins and histone post-translational modifications. The figure below shows how DNA torsional curves (hat curves) obtained with magnetic tweezers can be used to study the effect of polycations on DNA torsional elasticity.
Authors | Title | Journal | Volume | Pages | Year |
C. Zurla, T. Samuely, G. Bertoni, F. Valle, G. Dietler, L. Finzi, D. Dunlap | "Integration Host Factor alters LacI-induced DNA looping" | Biophysical Chemistry | 128 | 245-252 | 2007 |
Paul Liebesny, Sachin Goyal, David Dunlap, Fereydoon Family and Laura Finzi | "Determination of the Number of Proteins Bound non-Specifically to DNA" | Journal of Physics: Condensed Matter | 22 | 414104 | 2010 |
Sachin Goyal, Chandler Fountain, David D. Dunlap, Fereydoon Family, Laura Finzi | "Stretching DNA to quantify non-specific binding" | PRE | 86 | 011905 | 2012 |
Qing Shao, Sachin Goyal, Laura Finzi and David Dunlap | "Physiological levels of salt and polyamines favor writhe and limit twist in DNA" | Macromolecules | 45 | 3188−3196 | 2012 |
David Dunlap, Ruth Yokoyama, Huiping Ling, He-Ying Sun, Kerry McGill, Simona Cugusi and John C. Lucchesi | "Distinct contributions of MSL complex subunits to the transcriptional enhancement responsible for dosage compensation in Drosophila" | NAR | doi:10.1093/nar/gks890 | 2012 |
Method | Used for |
TPM | to measure bending elasticity |
MTs | to measure torsional elasticity and how bending and torsional elasticity depend on the tension applied to DNA or the chromatin fiber |
to measure persistence length |