Enhanced Cleavage at Abasic Sites within Clustered Lesions in Nucleosome Core Particles.

ABSTRACT: Clustered lesions are a hallmark of γ-radiolysis, but are produced by other damaging agents as well. Bistranded clustered lesions are precursors to double-strand breaks and are challenging to repair, thus making them an especially deleterious form of DNA damage. An abasic site (AP) is an alkaline-labile lesion frequently present in clustered lesions. Strand scission at an AP site is accelerated ≈100-fold in nucleosome core particles (NCPs). We examined how AP reactivity was affected within clustered lesions in NCPs. The rate constant of strand scission is increased as much as 2.5-fold in the presence of a proximal abasic site or thymidine glycol in the complementary strand. A proximal mispair has a similar effect on AP reactivity. Increased AP reactivity within a clustered lesion correlate

SUBMITTER: Yang K 

PROVIDER: S-EPMC6172155 | biostudies-literature | 2018 Oct

REPOSITORIES: biostudies-literature