Direct Fluorescence Monitoring of DNA Base Excision Repair

Uracil is an undesired component of DNA, as it arises from spontaneous deamination of cytosine.[1] This hydrolysis reaction promotes mutations, since the resulting U-G pair can be misread during DNA replication. As a result, multiple cellular enzymes have evolved to detect uracil in DNA and remove it prior to replication.[2] In E. coli uracil DNA glycosylase (UDG) enzyme functions to guard the bacterial genome. In humans, similar enzyme activities exist, including the proteins UNG1/2, SMUG, and TDG.[3] These enzymes flip uracil out of the DNA helix and cleave it from its deoxyribose sugar, leaving an abasic site in its place.[4]