Biochemists have pinpointed how a flaw in DNA that is central to mutations in cancer and aging fools the cellular enzyme that copies DNA. Their finding explains how oxidative DNA damage -- a process long believed to underlie cancers and aging -- can create permanent genetic damage. The Duke University Medical Center researchers’ findings were published online Aug. 22, 2004, by the journal Nature. The scientists were led by Associate Professor of Biochemistry Lorena Beese, Ph.D., and the paper’s lead author was Gerald Hsu, a Duke M.D./Ph.D. student. The other co-authors are Thomas Carell and Matthias Ober of Ludwig Maximillians University in Germany. Their research was supported mainly by the National Cancer Institute.