The structural location of DNA lesions in nucleosome core particles determines accessibility by base excision repair enzymes

Abstract

Background: Base excision repair is hindered by nucleosomes Results: Outwardly oriented uracils near the nucleosome center are efficiently cleaved; however, polymerase β is strongly inhibited at these sites. Conclusion: The histone octamer presents different levels of constraints on BER, dependent on the structural requirements for enzyme activity. Significance: Chromatin remodeling is necessary to prevent accumulation of aborted intermediates in nucleosomes. Copyright © 2013 by The American Society for Biochemistry and Molecular Biology, Inc.