COLL 15 |
| Raymond W. Friddle1, Ronald J. Baskin2, and Aleksandr Noy1. (1) Chemistry and Materials Science, Lawrence Livermore National Laboratory, Livermore, CA 94551, (2) Biophysics Group, University of California, Davis, 3243 Life Sciences Addition, Davis, CA 95616 |
| We used high resolution Atomic Force Microscopy (AFM) to image the compaction of linear and circular DNA by the yeast mitochondrial HMG protein ABF2. AFM images show compaction to be a strong function of ABF2 concentration in both the linear and circular DNA systems. Compaction of linear DNA was quantified by measuring the end-to-end distance of the chain at increasing concentrations of ABF2. We also derived a polymer statistical mechanics model that gives quantitative description of compaction observed in our experiments. Fit of the model to the data is improved when we modify it to allow cooperative binding. We use the model to determine binding characteristics for ABF2p. |
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Nanoscale Imaging of Biological Systems
Division of Colloid and Surface Chemistry |