Quantifying the stability of oxidatively damaged DNA by single-molecule DNA stretching.

ABSTRACT: One of the most common DNA lesions is created when reactive oxygen alters guanine. 8-oxo-guanine may bind in the anti-conformation with an opposing cytosine or in the syn-conformation with an opposing adenine paired by transversion, and both conformations may alter DNA stability. Here we use optical tweezers to measure the stability of DNA hairpins containing 8-oxoguanine (8oxoG) lesions, comparing the results to predictive models of base-pair energies in the absence of the lesion. Contrasted with either a canonical guanine-cytosine or adenine-thymine pair, an 8oxoG-cytosine base pair shows significant destabilization of several kBT. The magnitude of destabilization is comparable to guanine-thymine 'wobble' and cytosine-thymine mismatches. Furthermore, the measured energy of 8oxoG-adenine

SUBMITTER: McCauley MJ 

PROVIDER: S-EPMC5934642 | biostudies-literature | 2018 May

REPOSITORIES: biostudies-literature