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Unencumbered Pol ? lyase activity in nucleosome core particles.

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 ? catalyzes two key enzymatic steps: 5'-dRP lyase gap trimming and template-directed DNA synthesis. Despite its biological significance, knowledge of Pol ? activities on NCPs is still limited. Here, we show that removal of the 5'-dRP block by Pol ? 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.

SUBMITTER: Rodriguez Y

PROVIDER: S-EPMC5587807 | biostudies-literature | 2017 Sep

REPOSITORIES: biostudies-literature

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Unencumbered Pol β lyase activity in nucleosome core particles.

Rodriguez Yesenia Y Howard Michael J MJ Cuneo Matthew J MJ Prasad Rajendra R Wilson Samuel H SH

Nucleic acids research 20170901 15

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 ...[more]

PMID: 28911106

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