Journal article
Base excision repair in nucleosomes lacking histone tails
DNA repair, Vol.4(2), pp.203-209
2005
Handle:
https://hdl.handle.net/2376/108454
PMID: 15590328
Abstract
Recently, we developed an in vitro system using human uracil DNA glycosylase (UDG), AP endonuclease (APE), DNA polymerase β (pol β) and rotationally positioned DNA containing a single uracil associated with a ‘designed’ nucleosome, to test short-patch base excision repair (BER) in chromatin. We found that UDG and APE carry out their catalytic activities with reduced efficiency on nucleosome substrates, showing a distinction between uracil facing ‘out’ or ‘in’ from the histone surface, while DNA polymerase β (pol β) is completely inhibited by nucleosome formation. In this report, we tested the inhibition of BER enzymes by the N-terminal ‘tails’ of core histones that take part in both inter- and intra-nucleosome interactions, and contain sites of post-translational modifications. Histone tails were removed by limited trypsin digestion of ‘donor’ nucleosome core particles and histone octamers were exchanged onto a nucleosome-positioning DNA sequence containing a single G:U mismatch. The data indicate that UDG and APE activities are not significantly enhanced with tailless nucleosomes, and the distinction between rotational settings of uracil on the histone surface is unaffected. More importantly, the inhibition of pol β activity is not relieved by removal of the histone tails, even though these tails interact with DNA in the G:U mismatch region. Finally, inclusion of X-ray cross complement group protein 1 (XRCC1) or Werner syndrome protein (WRN) had no effect on the BER reactions. Thus, additional activities may be required in cells for efficient BER of at least some structural domains in chromatin.
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Details
- Title
- Base excision repair in nucleosomes lacking histone tails
- Creators
- Brian C Beard - Biochemistry and Biophysics, School of Molecular Biosciences, Washington State University, Pullman, WA 99164-4660, USAJill J Stevenson - Biochemistry and Biophysics, School of Molecular Biosciences, Washington State University, Pullman, WA 99164-4660, USASamuel H Wilson - The Laboratory of Structural Biology, NIEHS, Research Triangle Park, NC 27709, USAMichael J Smerdon - Biochemistry and Biophysics, School of Molecular Biosciences, Washington State University, Pullman, WA 99164-4660, USA
- Publication Details
- DNA repair, Vol.4(2), pp.203-209
- Academic Unit
- Molecular Biosciences, School of
- Publisher
- Elsevier B.V
- Identifiers
- 99900547401101842
- Language
- English
- Resource Type
- Journal article