Figure 3.

Recognition of deaminated bases in DNA by archaeal B family DNA polymerases by the read-ahead mechanism. The deaminated base products uracil (U) and hypoxanthine (X) were positioned further downstream from the 3′-end of the primer to determine the exact position of the replication block. Sequence details of the relevant parts of oligonucleotide substrates as well as the exact positions of the lesions on the gels are shown in the picture. The order of experimental lanes on the gels is schematically shown as well. The enzymes used were S.solfataricus PolY1 and PolB1 as well as the control DNA polymerases Taq from T.aquaticus and Pfu from Pyrococcus furiosus.