G/T mismatch-specific thymine DNA glycosylase (EC 3.2.2.29) (Thymine-DNA glycosylase) (hTDG)
1_MEAEN 6_ AGSYS 11_ LQQAQ 16_ AFYTF 21_ PFQQL 26_ MAEAP 31_ NMAVV 36_ NEQQM 41_ PEEVP 46_ APAPA 51_ QEPVQ 56_ EAPKG 61_ RKRKP 66_ RTTEP 71_ KQPVE 76_ PKKPV 81_ ESKKS 86_ GKSAK 91_ SKEKQ 96_ EKITD 101_ TFKVK 106_ RKVDR 111_ FNGVS 116_ EAELL 121_ TKTLP 126_ DILTF 131_ NLDIV 136_ IIGIN 141_ PGLMA 146_ AYKGH 151_ HYPGP 156_ GNHFW 161_ KCLFM 166_ SGLSE 171_ VQLNH 176_ MDDHT 181_ LPGKY 186_ GIGFT 191_ NMVER 196_ TTPGS 201_ KDLSS 206_ KEFRE 211_ GGRIL 216_ VQKLQ 221_ KYQPR 226_ IAVFN 231_ GKCIY 236_ EIFSK 241_ EVFGV 246_ KVKNL 251_ EFGLQ 256_ PHKIP 261_ DTETL 266_ CYVMP 271_ SSSAR 276_ CAQFP 281_ RAQDK 286_ VHYYI 291_ KLKDL 296_ RDQLK 301_ GIERN 306_ MDVQE 311_ VQYTF 316_ DLQLA 321_ QEDAK 326_ KMAVK 331_ EEKYD 336_ PGYEA 341_ AYGGA 346_ YGENP 351_ CSSEP 356_ CGFSS 361_ NGLIE 366_ SVELR 371_ GESAF 376_ SGIPN 381_ GQWMT 386_ QSFTD 391_ QIPSF 396_ SNHCG 401_TQEQE
1: DNA glycosylase that plays a key role in active DNA demethylation: specifically recognizes and binds 5-formylcytosine (5fC) and 5-carboxylcytosine (5caC) in the context of CpG sites and mediates their excision through base-excision repair (BER) to install an unmethylated cytosine. Cannot remove 5-hydroxymethylcytosine (5hmC). According to an alternative model, involved in DNA demethylation by mediating DNA glycolase activity toward 5-hydroxymethyluracil (5hmU) produced by deamination of 5hmC. Also involved in DNA repair by acting as a thymine-DNA glycosylase that mediates correction of G/T mispairs to G/C pairs: in the DNA of higher eukaryotes, hydrolytic deamination of 5-methylcytosine to thymine leads to the formation of G/T mismatches. Its role in the repair of canonical base damage is however minor compared to its role in DNA demethylation. It is capable of hydrolyzing the carbon-nitrogen bond between the sugar-phosphate backbone of the DNA and a mispaired thymine. In addition to the G/T, it can remove thymine also from C/T and T/T mispairs in the order G/T >> C/T > T/T. It has no detectable activity on apyrimidinic sites and does not catalyze the removal of thymine from A/T pairs or from single-stranded DNA. It can also remove uracil and 5-bromouracil from mispairs with guanine