該基因編碼的蛋白屬于TDG/mug DNA糖基化酶家族胸腺嘧啶DNA糖基化酶（TDG）通過水解DNA糖磷酸骨架與錯配胸腺嘧啶之間的碳氮鍵，從G/T錯配中去除胸腺嘧啶部分由于活性較低，這種酶也能去除c/t和t/t錯配的胸腺嘧啶。tdg還可以去除尿嘧啶和5-溴脲醛與鳥嘌呤的錯配。這種酶在細胞防御5-甲基胞嘧啶和胞嘧啶自發脫氨引起的基因突變中起著中心作用。這個基因可能在12號染色體的p臂上有一個假基因。
The protein encoded by this gene belongs to the TDG/mug DNA glycosylase family. Thymine-DNA glycosylase (TDG) removes thymine moieties from G/T mismatches by hydrolyzing the carbon-nitrogen bond between the sugar-phosphate backbone of DNA and the mispaired thymine. With lower activity, this enzyme also removes thymine from C/T and T/T mispairings. TDG can also remove uracil and 5-bromouracil from mispairings with guanine. This enzyme plays a central role in cellular defense against genetic mutation caused by the spontaneous deamination of 5-methylcytosine and cytosine. This gene may have a pseudogene in the p arm of chromosome 12.