ORGN 691 |
| The movement of a DNA base from an intrahelical, base-paired position to an extrahelical, solvent exposed position is termed base flipping. In the catalytically active state of most DNA repair and modification enzymes in complex with their substrate DNA the target base(s) are flipped-out of the duplex. There are two possibilities for the molecular recognition of damaged DNA bases by repair enzymes: 1) the enzyme recognizes a flipped-out damaged base or, 2) the site of the damaged base is recognized and the base is flipped-out into the enzyme. Damaged bases, such as the thymine dimer, destabilize the duplex DNA and may have a higher propensity for base flipping than non-damaged bases. To study this phenomenon, a base flipping assay was developed in which a flipped-out thymine is selectively recognized by a zinc-cyclen unit with a fluorescent reporter, dansyl. The atomistic details of base flipping have also been studied using potential of mean force calculations with a two-dimensional pseudodihedral coordinate.
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Asymmetric Reactions, Combinatorial Chemistry, Molecular Recognition and Self-Assembly, Proteins, Peptides, Amino Acids and Enzyme Inhibitors
8:00 PM-10:00 PM, Wednesday, March 28, 2007 Hyatt Regency Chicago -- Riverside Center, Poster
Division of Organic Chemistry |
