Intrinsic apurinic/apyrimidinic (AP) endonuclease activity enables Bacillus subtilis DNA polymerase X to recognize, incise, and further repair abasic sites

The N-glycosidic bond can be hydrolyzed spontaneously or by glycosylases during removal of damaged bases by the base excision repair pathway, leading to the formation of highly mutagenic apurinic/apyrimidinic (AP) sites. Organisms encode for evolutionarily conserved repair machinery, including speci...

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Detalles Bibliográficos
Autores: Baños, Benito, Villar, Laurentino, Salas, Margarita, Vega, Miguel de
Tipo de recurso: artículo
Fecha de publicación:2010
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/34085
Acceso en línea:http://hdl.handle.net/10261/34085
Access Level:acceso abierto
Palabra clave:Apurinic/apyrimidinic-lyase
Site-directed mutagenesis
Descripción
Sumario:The N-glycosidic bond can be hydrolyzed spontaneously or by glycosylases during removal of damaged bases by the base excision repair pathway, leading to the formation of highly mutagenic apurinic/apyrimidinic (AP) sites. Organisms encode for evolutionarily conserved repair machinery, including specific AP endonucleases that cleave the DNA backbone 5′ to the AP site to prime further DNA repair synthesis. We report on the DNA polymerase X from the bacteriumBacillus subtilis (PolXBs) that, along with polymerization and 3′–5′-exonuclease activities, possesses an intrinsic AP-endonuclease activity. Both, AP-endonuclease and 3′–5′-exonuclease activities are genetically linked and governed by the same metal ligands located at the C-terminal polymerase and histidinol phosphatase domain of the polymerase. The different catalytic functions of PolXBs enable it to perform recognition and incision at an AP site and further restoration (repair) of the original nucleotide in a standalone AP-endonuclease-independent way.