Figure 4

Test of GlnR binding by gel retardation assays. 200– 300 bp DNA fragments upstream of GlnR target genes labeled with digoxigenin were used. For each gene free DNA (lane 1), DNA plus 400 ng MBP-GlnR (lane 2) and DNA plus 400 ng MBP-GlnR plus 3 μg competitor DNA polyd[I-C] (lane 3) was tested. (A) Target genes with specific binding; (B) unspecific or no binding.