δDLX5 does not interact with DNA or exhibit homeodomain-dependent protein–protein interactions. A,Gel mobility shift analysis was performed as described (Zhang et al., 1997), using DLX5 or δDLX5 proteins obtained by in vitro transcription/translation (1.0 or 2.5 μl, as indicated by the triangle). Sequences of the DNA sites that were used are shown (Catron et al., 1993). The lane labeledNA represents unprogrammed lysate. B, GST protein interaction assay was performed by using³⁵S-labeled DLX5 or δDLX5 proteins (5 μl) and a GST or GST–MSX1 fusion protein (5 μg). The ³⁵S-labeled proteins were immobilized on GST resin and resolved by SDS-polyacrylamide gel electrophoresis, followed by autoradiography. The input lanes contain 20% (1 μl) of the total ³⁵S-labeled protein that was used in the GST interaction assay, and the marker lane shows the positions of ¹⁴C-labeled molecular size standards corresponding to 46, 31, and 19 kDa (arrowheads).