BIOL 111 |
| Long-range hole transport in DNA has been extensively studied in isolated DNA constructs. However, little is known about this phenomenon in the eukaryotic cell nucleus. Contrary to the structure of short DNA duplexes in a homogenous aqueous environment, nuclear DNA is found in a highly ordered protein-nucleic acid structure known as chromatin. The fundamental level of DNA compaction is the nucleosome core particle (NCP), consisting of ~147 base pairs of DNA wrapped one and a quarter turns around an octamer of histone proteins. In the studies reported here, we show that packaging DNA into a NCP i) decreases the yields of oxidized damage and ii) perturbs the dynamics of DNA hole transport. To site-selectively inject an excess positive charge into DNA, we have utilized a covalent Anthraquinone photooxidant. Two different DNA sequences were investigated and the dynamics of DNA hole transport within them are compared and contrasted. Structural characterization of these NCPs has allowed us to correlate the observed changes in DNA hole transport dynamics with the changes in DNA structure observed in prior X-ray crystal structures of the NCP. |
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Chemistry and Metabolism
4:30 PM-6:30 PM, Tuesday, 12 September 2006 Moscone Center -- Hall D, Poster
Division of Biological Chemistry |