The nucleoid-associated protein HU enhances 8-oxoguanine base excision by the formamidopyrimidine-DNA glycosylase.
Biochem J
; 471(1): 13-23, 2015 Oct 01.
Article
em En
| MEDLINE
| ID: mdl-26392572
ABSTRACT
The nucleoid-associated protein HU is involved in numerous DNA transactions and thus is essential in DNA maintenance and bacterial survival. The high affinity of HU for SSBs (single-strand breaks) has suggested its involvement in DNA protection, repair and recombination. SSB-containing DNA are major intermediates transiently generated by bifunctional DNA N-glycosylases that initiate the BER (base excision repair) pathway. Enzyme kinetics and DNA-binding experiments demonstrate that HU enhances the 8-oxoguanine-DNA glycosylase activity of Fpg (formamidopyrimidine-DNA glycosylase) by facilitating the release of the enzyme from its final DNA product (one nucleoside gap). We propose that the displacement of Fpg from its end-DNA product by HU is an active mechanism in which HU recognizes the product when it is still bound by Fpg. Through DNA binding, the two proteins interplay to form a transient ternary complex Fpg/DNA/HU which results in the release of Fpg and the molecular entrapment of SSBs by HU. These results support the involvement of HU in BER in vivo.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
DNA Bacteriano
/
Proteínas de Escherichia coli
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DNA-Formamidopirimidina Glicosilase
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Proteínas de Ligação a DNA
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Reparo do DNA
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Escherichia coli
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Quebras de DNA de Cadeia Dupla
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Guanina
Tipo de estudo:
Risk_factors_studies
Idioma:
En
Revista:
Biochem J
Ano de publicação:
2015
Tipo de documento:
Article
País de afiliação:
França