Surviving an oxygen atmosphere: DNA damage and repair

CHED 1464

Cynthia J. Burrows, Department of Chemistry, University of Utah, 315 S. 1400 East, Salt Lake City, UT 84112-0850
Eukaryotes emerged about 2 billion years ago in response to increasing levels of O2 in the atmosphere. As a consequence of life's coexistence with this reactive diradical, as well as the other reactive oxygen species generated in the respiratory process of converting O2 to H2O, cells have adapted biochemical processes to protect themselves from free radical damage. Nevertheless, it is estimated that each cell's genomic DNA undergoes thousands of oxidative damage events per day, and even more under conditions of stress. Oxidative damage to DNA, if unrepaired, leads to mutations that underlie cancer, aging and neurological disease. The molecular events leading to oxidative damage, as well as the DNA polymerase and repair enzymes that have evolved to deal with these lesions, will be outlined in this report.