FIGURE 1.

Chloroplast glycosylase-lyase/endonuclease activity. A, immunoblot analysis of chloroplast proteins from wild-type (Col-0). CP, chloroplast proteins; TP, total leaf proteins; CSD2, chloroplast stromal marker; CSD1, cytosolic marker; histone H3, nuclear marker; porin, mitochondrial marker. B, glycosylase-lyase/endonuclease activity assay. Supercoiled plasmid substrate was incubated for 7 min at 37 °C with replicate chloroplast protein preparations (lanes 1–4), E. coli Nth as a positive control (lanes 5 and 6), or no protein (lanes 7 and 8) and then run on a 1% agarose gel. +, lanes with OsO₄-treated plasmid; −, untreated control plasmid; OC, relaxed open circular plasmid product; SC, supercoiled plasmid substrate.