The enigmatic thymine DNA glycosylase.

Bibliographic Collection: 
MOCA Reference, APE
Publication Type: Journal Article
Authors: Cortázar, Daniel; Kunz, Christophe; Saito, Yusuke; Steinacher, Roland; Schär, Primo
Year of Publication: 2007
Journal: DNA Repair (Amst)
Volume: 6
Issue: 4
Pagination: 489-504
Date Published: 2007 Apr 1
Publication Language: eng
ISSN: 1568-7864
Keywords: Amino Acid Sequence, DNA Mismatch Repair, DNA Repair, Evolution, Molecular, Humans, Molecular Sequence Data, Protein Conformation, Sequence Alignment, Thymine DNA Glycosylase

When it was first isolated from extracts of HeLa cells in Josef Jiricny's laboratory, the thymine DNA glycosylase (TDG) attracted attention because of its ability to remove thymine, i.e. a normal DNA base, from G.T mispairs. This implicated a function of DNA base excision repair in the restoration of G.C base pairs following the deamination of a 5-methylcytosine. TDG turned out to be the founding member of a newly emerging family of mismatch-directed uracil-DNA glycosylases, the MUG proteins, that act on a comparably broad spectrum of base lesion including G.U as the common, most efficiently processed substrate. However, because of its apparent catalytic inefficiency, some have considered TDG a poor DNA repair enzyme without an important biological function. Others have reported 5-meC DNA glycosylase activity to be associated with TDG, thrusting the enzyme into limelight as a possible DNA demethylase. Yet others have found the glycosylase to interact with transcription factors, implicating a function in gene regulation, which appears to be critically important in developmental processes. This article reviews all these developments in view of possible biological functions of this multifaceted DNA glycosylase.

DOI: 10.1016/j.dnarep.2006.10.013
Alternate Journal: DNA Repair (Amst.)
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