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Polymorphism of apyrimidinic DNA structures in the nucleosome.

ABSTRACT: Huge amounts (>10,000/day) of apurinic/apyrimidinic (AP) sites are produced in genomes, but their structures in chromatin remain undetermined. We determined the crystal structure of the nucleosome containing AP-site analogs at two symmetric sites, which revealed structural polymorphism: one forms an inchworm configuration without an empty space at the AP site, and the other forms a B-form-like structure with an empty space and the orphan base. This unexpected inchworm configuration of the AP site is important to understand the AP DNA repair mechanism, because it may not be recognized by the major AP-binding protein, APE1, during the base excision repair process.

SUBMITTER: Osakabe A

PROVIDER: S-EPMC5282573 | biostudies-literature | 2017 Jan

REPOSITORIES: biostudies-literature

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Polymorphism of apyrimidinic DNA structures in the nucleosome.

Osakabe Akihisa A Arimura Yasuhiro Y Matsumoto Syota S Horikoshi Naoki N Sugasawa Kaoru K Kurumizaka Hitoshi H

Scientific reports 20170131

Huge amounts (>10,000/day) of apurinic/apyrimidinic (AP) sites are produced in genomes, but their structures in chromatin remain undetermined. We determined the crystal structure of the nucleosome containing AP-site analogs at two symmetric sites, which revealed structural polymorphism: one forms an inchworm configuration without an empty space at the AP site, and the other forms a B-form-like structure with an empty space and the orphan base. This unexpected inchworm configuration of the AP sit ...[more]

PMID: 28139742

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