Table 1.
Nuclear and Mitochondrial Human DNA Glycosylases
| FAMILY Fold | ISOFORMS | |||
|---|---|---|---|---|
| GLYCOSYLASE | Nuclear | Mitochondrial | SUBSTRATES | |
|
| ||||
| UDG | UNG | UNG2 | UNG1 | U, 5-FU & ssDNA, dsDNA |
| TDG | TDG | NF | T:G, U:G, εC:G, 5-FU, Tg:G & dsDNA>>ssDNA | |
| SMUG1 | SMUG1 | NF | U, 5-hmU, 5-hmC, 5-FU & ssDNA, dsDNA | |
|
| ||||
| AAG | AAG/MPG | A,B,C | A, B | 3-meA, 7-meG, 1-meG, Hx, U, εG, εA & ssDNA, dsDNA |
|
| ||||
| Helix-hairpin-helix | NTHL1 | NTHL1 | NTHL1 | Tg, 5-hC, 5-hU, Fapy lesions & ssDNA, dsDNA |
| OGG1 | 1a | 1b, 1c; 2a – 2e | 8-oxoG, Fapy lesions & dsDNA | |
| MUTYH | β, γ | α | A:8-oxoG, A:G, and A:C, 2-OHA:G & dsDNA | |
| MBD4 | MBD4 | NF | T:G, U:G, 5-MeC, halogenated pyrimidines, 5-FU, Tg:G & dsDNA | |
|
| ||||
| Fpg/Nei Helix-two turns-helix | NEIL1 | NEIL1 | NEIL1 | Sp, Gh, Tg, DHU, 5-OHU, 5-OHC, DHT, FapyG, FapyA & dsDNA>bubble, bulge, fork>ssDNA |
| NEIL2 | NEIL2 | NEIL2 | Sp, Gh, DHT, DHU, 5-OHU, 5-OHC & ssDNA>bubble, bulge, fork>dsDNA | |
| NEIL3 | NEIL3 | NF | Sp, Gh, FapyG, FapyA, MeFapyG, DHU, DHT, 5-OHU, 5-OHC, Tg & ssDNA>dsDNA | |
Isoforms specific for the mitochondria or the nucleus have been described so far for AAG, OGG1 and MUTYH. The substrate preferences for each glycosylase listed in Table 1 have been reviewed extensively [Brooks et al., 2013; Jacobs and Schar, 2012; Liu et al., 2013; Prakash et al., 2012]. NF, not found in the mitochondria.