Types of Glycosylases
Crystal structures of many glycosylases have been solved. Based on structural similarity, glycosylases are grouped into four superfamilies. The UDG and AAG families contain small, compact glycosylases, whereas the MutM/Fpg and HhH-GPD families comprise larger enzymes with multiple domains.
A wide variety of glycosylases have evolved to recognize different damaged bases. The table below summarizes the properties of known glycosylases in commonly studied model organisms.
| E. coli | Yeast (S. cerevisiae) | Human | Type | Substrates |
|---|---|---|---|---|
| AlkA | Mag1 | MPG | monofunctional | 3-meA, hypoxanthine |
| UDG | Ung1 | UNG | monofunctional | uracil |
| Fpg | Ogg1 | hOGG1 | bifunctional | 8-oxoG, FapyG |
| Nth | Ntg1 | hNTH1 | bifunctional | Tg, hoU, hoC, urea, FapyG |
| Ntg2 | ||||
| Nei | Not present | hNEIL1 | bifunctional | Tg, hoU, hoC, urea, FapyG, FapyA |
| hNEIL2 | AP site, hoU | |||
| hNEIL3 | unknown | |||
| MutY | Not present | hMYH | monofunctional | A:8-oxoG |
| Not present | Not present | hSMUG1 | monofunctional | U, hoU, hmU, fU |
| Not present | Not present | TDG | monofunctional | T:G mispair |
| Not present | Not present | MBD4 | monofunctional | T:G mispair |
DNA glycosylases can be grouped into the following categories based on their substrate(s):
Read more about this topic: DNA Glycosylase
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