Figure 6.

goosecoid, Xotx2, and Mix.1 bind to the −174/−152 region of the Xbra2 promoter. goosecoid, Xotx2, and Mix.1 were translated in a coupled transcription–translation system; the DNA template used in each reaction is indicated above the brackets. In some cases, binding reactions were preincubated with a 200-fold molar excess of specific competitor (unlabeled −174/−152 oligonucleotide, S) or with a 200-fold molar excess of irrelevant competitor (unlabeled −43/−19 oligonucleotide, I). Complexes were resolved on a 4% polyacrylamide gel. The asterisk (*) indicates the position of a nonspecific DNA-binding complex; this complex varied between lanes and between different experiments.