FIG. 2.

SATB1 and CDP interaction in vitro. (A) Mapping of the SATB1 region necessary for CDP association. GST-CDP (CR2-Cterm) was immobilized on glutathione-agarose beads and incubated with ³⁵S-labeled in vitro-translated full-length SATB1 (lanes 1 and 2), SATB1 mutants with C-terminal truncations (lanes 3 to 12), an internal-deletion mutant (lanes 13 and 14), or GST alone (lanes 15 and 16). After affinity chromatography, bound proteins were resolved on SDS–10% polyacrylamide gels (even-numbered lanes) and compared with input labeled protein (odd-numbered lanes). (B) Lack of DNA binding of internally deleted SATB1. Wild-type SATB1 and an internal-deletion mutant were purified and used for gel shift assays with a labeled 120-bp proximal NRE probe prior to electrophoresis on a 4% nondenaturing polyacrylamide gel. The 120-bp NRE probe contains two binding sites for CDP and two binding sites for SATB1 (59). Numbers indicate amino acid positions.