Homo sapiens L. (human) [HSA]

FULL NAME: G/T mismatch-specific thymine DNA glycosylase


DESCRIPTION:
In the DNA of higher eukaryotes, hydrolytic deamination of 5-methylcytosine to thymine leads to the formation of G/T mismatches. This enzyme corrects G/T mispairs to G/C pairs. 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.

STRUCTURE SIMILARITY:
Belongs to the TDG/mug DNA glycosylase family.


CATALYTIC ACTIVITY:
Hydrolyzes mismatched double-stranded DNA and polynucleotides, releasing free thymine.


POST-TRANSLATIONAL MODIFICATION:
Sumoylation on Lys-330 by either SUMO1 or SUMO2 induces dissociation of the product DNA.


PROTEIN TYPE(S):
DNA N-glycosylase


RELATED PATHWAY(S):
base excision repair (BER)


RELATED DAMAGE:
5-fluoro-dU
3,N4-etheno-C (εC) in dsDNA
deoxyuridine
dU from U:G
T from T:G
5-hydroxymethyl U (5-OH-me-U)
5-bromoU
ethenoC from ethenoC:G
T from T:C
T from T:T
T from T:O6-meG


Amino acids sequence

        10         20         30         40         50         60
MEAENAGSYS LQQAQAFYTF PFQQLMAEAP NMAVVNEQQM PEEVPAPAPA QEPVQEAPKG
        70         80         90        100        110        120
RKRKPRTTEP KQPVEPKKPV ESKKSGKSAK SKEKQEKITD TFKVKRKVDR FNGVSEAELL
       130        140        150        160        170        180
TKTLPDILTF NLDIVIIGIN PGLMAAYKGH HYPGPGNHFW KCLFMSGLSE VQLNHMDDHT
       190        200        210        220        230        240
LPGKYGIGFT NMVERTTPGS KDLSSKEFRE GGRILVQKLQ KYQPRIAVFN GKCIYEIFSK
       250        260        270        280        290        300
EVFGVKVKNL EFGLQPHKIP DTETLCYVMP SSSARCAQFP RAQDKVHYYI KLKDLRDQLK
       310        320        330        340        350        360
GIERNMDVQE VQYTFDLQLA QEDAKKMAVK EEKYDPGYEA AYGGAYGENP CSSEPCGFSS
       370        380        390        400        410
NGLIESVELR GESAFSGIPN GQWMTQSFTD QIPSFSNHCG TQEQEEESHA 

Encoded by TDG gene

FULL NAME: thymine-DNA glycosylase


DESCRIPTION:
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. [provided by RefSeq, Jul 2008]


Nucleic acid sequence

        10         20         30         40         50         60
atggaagcgg agaacgcggg cagctattcc cttcagcaag ctcaagcttt ttatacgttt
        70         80         90        100        110        120
ccatttcaac aactgatggc tgaagctcct aatatggcag ttgtgaatga acagcaaatg
       130        140        150        160        170        180
ccagaagaag ttccagcccc agctcctgct caggaaccag tgcaagaggc tccaaaagga
       190        200        210        220        230        240
agaaaaagaa aacccagaac aacagaacca aaacaaccag tggaacccaa aaaacctgtt
       250        260        270        280        290        300
gagtcaaaaa aatctggcaa gtctgcaaaa tcaaaagaaa aacaagaaaa aattacagac
       310        320        330        340        350        360
acatttaaag taaaaagaaa agtagaccgt tttaatggtg tttcagaagc tgaacttctg
       370        380        390        400        410        420
accaagactc tccccgatat tttgaccttc aatctggaca ttgtcattat tggcataaac
       430        440        450        460        470        480
ccgggactaa tggctgctta caaagggcat cattaccctg gacctggaaa ccatttttgg
       490        500        510        520        530        540
aagtgtttgt ttatgtcagg gctcagtgag gtccagctga accatatgga tgatcacact
       550        560        570        580        590        600
ctaccaggga agtatggtat tggatttacc aacatggtgg aaaggaccac gcccggcagc
       610        620        630        640        650        660
aaagatctct ccagtaaaga atttcgtgaa ggaggacgta ttctagtaca gaaattacag
       670        680        690        700        710        720
aaatatcagc cacgaatagc agtgtttaat ggaaaatgta tttatgaaat ttttagtaaa
       730        740        750        760        770        780
gaagtttttg gagtaaaggt taagaacttg gaatttgggc ttcagcccca taagattcca
       790        800        810        820        830        840
gacacagaaa ctctctgcta tgttatgcca tcatccagtg caagatgtgc tcagtttcct
       850        860        870        880        890        900
cgagcccaag acaaagttca ttactacata aaactgaagg acttaagaga tcagttgaaa
       910        920        930        940        950        960
ggcattgaac gaaatatgga cgttcaagag gtgcaatata catttgacct acagcttgcc
       970        980        990       1000       1010       1020
caagaggatg caaagaagat ggctgttaag gaagaaaaat atgatccagg ttatgaggca
      1030       1040       1050       1060       1070       1080
gcatatggtg gtgcttacgg agaaaatcca tgcagcagtg aaccttgtgg cttctcttca
      1090       1100       1110       1120       1130       1140
aatgggctaa ttgagagcgt ggagttaaga ggagaatcag ctttcagtgg cattcctaat
      1150       1160       1170       1180       1190       1200
gggcagtgga tgacccagtc atttacagac caaattcctt cctttagtaa tcactgtgga
      1210       1220       1230
acacaagaac aggaagaaga aagccatgct taa  

Last modification date: Oct. 2, 2011