Abstract
To investigate the role of chromatin remodeling in nucleotide excision repair, we prepared mononucleosomes with a 200-bp duplex containing an acetylaminofluorene-guanine (AAF-G) adduct at a single site. DNase I footprinting revealed a well-phased nucleosome structure with the AAF-G adduct near the center of twofold symmetry of the nucleosome core. This mononucleosome substrate was used to examine the effect of the SWI/SNF remodeling complex on the activity of human excision nuclease reconstituted from six purified excision repair factors. We found that the three repair factors implicated in damage recognition, RPA, XPA, and XPC, stimulate the remodeling activity of SWI/SNF, which in turn stimulates the removal of the AAF-G adduct from the nucleosome core by the excision nuclease. This is the first demonstration of the stimulation of nucleotide excision repair of a lesion in the nucleosome core by a chromatin-remodeling factor and contrasts with the ACF remodeling factor, which stimulates the removal of lesions from internucleosomal linker regions but not from the nucleosome core.
Publication types
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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2-Acetylaminofluorene / analogs & derivatives*
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2-Acetylaminofluorene / chemistry
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2-Acetylaminofluorene / metabolism
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Base Sequence
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Chromatin / chemistry*
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Chromatin / metabolism
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DNA / chemistry*
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DNA Footprinting
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DNA Ligases / chemistry
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DNA Repair / physiology*
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DNA-Binding Proteins / chemistry
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Deoxyguanosine / analogs & derivatives*
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Deoxyguanosine / chemistry
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Deoxyguanosine / metabolism
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Deoxyribonucleases / chemistry*
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Drosophila Proteins*
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Enzyme Activation / physiology
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Humans
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Macromolecular Substances
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Models, Biological
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Molecular Sequence Data
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Nucleosomes / chemistry*
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Nucleosomes / metabolism
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RNA-Binding Proteins / chemistry
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Replication Protein A
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Ribonucleoprotein, U1 Small Nuclear / chemistry
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Substrate Specificity
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Xeroderma Pigmentosum Group A Protein
Substances
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Chromatin
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DNA-Binding Proteins
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Drosophila Proteins
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Macromolecular Substances
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Nucleosomes
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RNA-Binding Proteins
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RPA1 protein, human
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Replication Protein A
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Ribonucleoprotein, U1 Small Nuclear
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XPA protein, human
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Xeroderma Pigmentosum Group A Protein
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snf protein, Drosophila
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XPC protein, human
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N-(deoxyguanosin-8-yl)acetylaminofluorene
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DNA
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2-Acetylaminofluorene
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Deoxyribonucleases
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DNA Ligases
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Deoxyguanosine