Efficient recognition of an unpaired lesion by a DNA repair glycosylase.

ABSTRACT: The duplex structure of DNA, with its internal base pairing, protects the nucleobases from chemical damage, but it also poses a barrier to DNA-modifying enzymes, including the enzymes that recognize and repair DNA damage. It is known that unpaired (or bulged) nucleotides are significantly more accessible, but it is not known whether they might be recognized by nucleotide-flipping enzymes. We have investigated this question with human alkyladenine DNA glycosylase (AAG). AAG recognizes a wide variety of structurally disparate lesions, including deoxyinosine (I), which results from the spontaneous oxidative deamination of adenosine, and catalyzes the hydrolysis of the N-glycosidic bond to release the lesion base and initiate the base excision repair pathway. We used single-turnover kinetics t

SUBMITTER: Lyons DM 

PROVIDER: S-EPMC2797315 | biostudies-literature | 2009 Dec

REPOSITORIES: biostudies-literature