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Updated: May 25, 2026

Detection of Modified Forms of Cytosine Using Sensitive Immunohistochemistry
Published on: August 16, 2016
Thymine DNA glycosylase specifically recognizes 5-carboxylcytosine-modified DNA
Liang Zhang1, Xingyu Lu, Junyan Lu
1Department of Chemistry and Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois, USA.
Abstract:
Human thymine DNA glycosylase (hTDG) efficiently excises 5-carboxylcytosine (5caC), a key oxidation product of 5-methylcytosine in genomic DNA, in a recently discovered cytosine demethylation pathway. We present here the crystal structures of the hTDG catalytic domain in complex with duplex DNA containing either 5caC or a fluorinated analog. These structures, together with biochemical and computational analyses, reveal that 5caC is specifically recognized in the active site of hTDG, supporting the role of TDG in mammalian 5-methylcytosine demethylation.
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