Unencumbered Pol β lyase activity in nucleosome core particles
Year: 2017
Type: article
Abstract: Packaging of DNA into the nucleosome core particle (NCP) is considered to exert constraints to all DNA-templated processes, including base excision repair where Pol β catalyzes two key enzymatic steps: 5'-dRP lyase gap trimming and template-directed DNA synthesis. Despite its biological significance, knowledge of Pol β activities on NCPs is still limited. Here, we show that removal of the 5'-dRP block by Pol β is unaffected by NCP constraints at all sites tested and is even enhanced near the DNA ends. In contrast, strong inhibition of DNA synthesis is observed. These results indicate 5'-dRP gap trimming proceeds unperturbed within the NCP; whereas, gap filling is strongly limited. In the absence of additional factors, base excision repair in NCPs will stall at the gap-filling step.
Source: Nucleic Acids Research
DOI: 10.1093/nar/gkx593
Language: English
Topic: DNA Repair Mechanisms
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $3,992
OpenAlex ID: W2735338880