The N-terminus of RPA large subunit and its spatial position are important for the 5'->3' resection of DNA double-strand breaks.
Nucleic Acids Res
; 43(18): 8790-800, 2015 Oct 15.
Article
en En
| MEDLINE
| ID: mdl-26227969
ABSTRACT
The first step of homology-dependent repair of DNA double-strand breaks (DSBs) is the resection of the 5' strand to generate 3' ss-DNA. Of the two major nucleases responsible for resection, EXO1 has intrinsic 5'->3' directionality, but DNA2 does not. DNA2 acts with RecQ helicases such as the Werner syndrome protein (WRN) and the heterotrimeric eukaryotic ss-DNA binding protein RPA. We have found that the N-terminus of the RPA large subunit (RPA1N) interacts with both WRN and DNA2 and is essential for stimulating WRN's 3'->5' helicase activity and DNA2's 5'->3' ss-DNA exonuclease activity. A mutant RPA complex that lacks RPA1N is unable to support resection in Xenopus egg extracts and human cells. Furthermore, relocating RPA1N to the middle subunit but not to the small subunit causes severe defects in stimulating DNA2 and WRN and in supporting resection. Together, these findings suggest that RPA1N and its spatial position are critical for restricting the directionality of the WRN-DNA2 resection pathway.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
ADN Helicasas
/
Proteínas de Xenopus
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Proteínas de Unión al ADN
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Reparación del ADN
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Endonucleasas
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Proteína de Replicación A
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Roturas del ADN de Doble Cadena
Límite:
Animals
/
Humans
Idioma:
En
Revista:
Nucleic Acids Res
Año:
2015
Tipo del documento:
Article
País de afiliación:
Estados Unidos