FIG. 10.

Molecular weight determination of the PRE-2 binding factor. PalK and PalF nuclear extracts were probed with a radiolabeled BrdU-substituted PRE-2 motif in a band shift assay. After UV exposure, the PRE-2 cross-linked protein complex was electrophoresed on an SDS–10% polyacrylamide gel. Competition band shift reactions with either 100-fold nonlabeled BrdU or 100-fold nonlabeled AP-1 were performed as indicated to assess the specificity of binding. Numbers at left are molecular masses in kilodaltons.