Figure 3.

Plant mitochondrial UDG and AP endonuclease activities are partially membrane-bound. Double-stranded oligodeoxyribonucleotides Oug (triangles), Oua (squares) and Oap (lozenges), [³²P]-labeled at the 5′-end of the strand carrying the lesion, were incubated for increasing times in the presence of a membrane fraction (A) or a soluble fraction (B) from A. thaliana whole mitochondria. The samples were subsequently denatured and fractionated by electrophoresis on polyacrylamide gels in the presence of 7 M urea. The corresponding autoradiograms were scanned and quantified with the ImageJ software (NIH), so as to estimate the percentage of lesion-specific incision at the different time points. Bars indicate standard deviation.