Figure 1.

HMGA2 acts as an AP lyase on abasic supercoiled DNA. (A) Cleavage assay with full-length HMGA2 or a peptide comprising the third AT-hook with abasic supercoiled (sc) DNA. AP site cleavage converts the topology of sc DNA into the open circular (oc) form. Note that depurinated input DNA is mostly sc and does not change during incubation without HMGA2. (B) Detection of in vitro trapped HMGA2 on AP site plasmid DNA using western blotting. The positions of HMGA2–DNA complexes detected on the western blot membrane are marked by arrows. (C) Cleavage and in vitro trapping assay with HMGA1a, HMGA1b and HMGA2 on abasic sc DNA.