October 09, 2015
Three chemists were awarded their field's 2015 Nobel Prize this week for mapping out the molecular process by which DNA repairs itself amid the thousands of spontaneous changes it undergoes on a daily basis.
In the 1970's, scientists believed that DNA was a stable molecule, but Swedish chemist Tomas Lindahl demonstrated that it decays to such an incredible extent that life on Earth should never have been possible. His examination of this mystery led him to the discovery of 'base excision repair,' which explains the biological process that safeguards genetic information and constantly prevents our DNA from collapsing.
Independently of one another, Lindahl, Stanford chemist Paul Modrich, and U.S.-Turkish chemist Aziz Sancar mapped the enzymatic mechanisms that allow DNA to fix damages and correct defects due to radiation, free radicals and other carcinogenic substances.
Lindahl's findings on 'base excision repair' revealed the corrective mechanism for different forms of lesions that affect DNA bases, limiting miscoding that would greatly compromise the structure of DNA.
Modrich has been honored for discovering the mechanism of mismatch repair, which reduces the frequency of errors by a thousandfold during the synthesis of new strands. When congenital defects in mismatch repair are present, individuals face increased likelihood of a hereditary variant of colon cancer.
Sancar mapped out the bacterial mechanism of 'nucleotide excision repair,' which helps cells repair UV damage to DNA and corrects other damages caused by mutagenic substances.
Learn more about the chemists' here.
