Extent of cleavage for indicated bases in duplex oligonucleotides by members of the human uracil glycosylase family.

Excision studies for analogs paired with G used a hyTDG-lyase (Y163K) to cleave the phosphodiester backbone whereas those paired with A were cleaved with NaOH. Values shown in the table represent the averages and standard deviations from three independent experiments. Cleavage of 5foU-containing oligonucleotides were adjusted for thermal hydrolysis by subtraction of cleavage observed in no enzyme controls. Cleavage of 5foC:A base pairs was adjusted for alkaline hydrolysis by subtraction of cleavage in no enzyme controls. Glycosylase excision of 5caC paired with A by hTDG was also measured using hyTDG-lyase (Y163K) and a value of 50.3±3.9% cleavage was observed. Phosphodiester backbone cleavage using the hyTDG-lyase (Y163K) underestimates glycosylase cleavage when the target pyrimidine is paired with A rather than G.