Archaeal Genome Guardians Give Insights into Eukaryotic DNA Replication and Damage Response Proteins

Figure 3

Representative structures of UDGs from families 1–5. (a) Family 1: bacterial UDG monomer with uracil from E. coli (PDB code 1FLZ) and E. coli UDG (PDB code 1UUG) bound to a Bacillus phage inhibitor (UDI). Eukaryotic UDG structures exemplified by apo G. morhua UDG (PDB code 1OKB) and DNA-bound human UDG (PDB code 1EMH). (b) Family 2: E. coli MUG in complex with DNA (PDB code 1MWJ); human TDG (PDB code 2RBA). (c) Family 3: X. laevis SMUG1 in complex with DNA (PDB code 1OE4). (d) Family 4: bacterial UDG (with Fe-S) from T. thermophilus UDG (PDB code 1 UI0). Determination of the X-ray structure from S. tokodaii will shed light on archaeal UDG homologs. (e) Family 5: T. thermophilus UDG (with Fe-S) bound to DNA (PDB code 2DEM). Archaea contain homologs from families 2, 4, and 5.