FIG. 3.

Altered N1 nucleoprotein structure correlates with transcriptional activity. Nuclei from K562 clones containing the indicated minichromosomes were digested with 0 or 200 U of MNase per ml or with 800 U of BamHI and PvuII per ml. Soluble, recovered nucleoprotein was analyzed by agarose gel electrophoresis and Southern blotting. The probe used corresponded to sequences within N1 (Fig. 2). (A) Ethidium bromide-stained agarose gel. (B) Southern blot of the gel shown in panel A. (C) A part of each sample was deproteinized and analyzed by agarose gel electrophoresis and Southern blotting. The membrane was successively hybridized with the N1 (C) and N2-N3 (D) probes indicated in Fig. 2.