Table 1.

Mutational Analysis of DNA Binding Motifs

Binding Site Sequencea	Percent Bindingb
TGACCC	100
AAACCC	64
AGACCC	54
TAACCC	20
TCACCC	7
TGAGCC	14
TGTCCC	<1
TGTGCC	<1
TGACGC	<1
AAACCG	<1
AAACCA	<1

^a Probes contained four direct repeats of the indicated sequence (top strand is given; substituted bases are underlined) as shown for multimers in Figure 4A. Double-stranded oligonucleotides were labeled with α-³²P-dCTP and tested by EMSA for binding by the ΔC-133 derivative.

^b The intensity of the signal in the DNA-protein complexes was quantified with Adobe Photoshop (Mountain View, CA), using the signal from the TGACCC binding site probe as 100%.