Figure 2.

A Nucleotide sequence of the promoter operator region of the desA gene containing the -10 and -35 boxes; the transcription start point is indicated as +1. The mRNA is indicated by a wavy line and the putative ribosome binding site GGAGG upstream of the first translated codon ATG is underlined. The convergent thick arrows indicate the palindromic sequence of binding of the DmdR protein (operator). The two vertical arrows indicate the DNA fragment used for the gel mobility shift experiments. B Electrophoretic mobility shift assay of the [³²P]labeled desA probe and DmdR protein from S. coelicolor. Lanes 1, labeled free desA probe; 2, labeled desA, mixed with DmdR (note the band shift); 3, labeled desA with excess unlabeled desA; 4, labeled desA with DmdR and anti-DmdR antibodies; 5, labeled desA with DmdR and 2,2'-dipyridyl (200 mM) without Mn²⁺; 6, labeled desA with DmdR and 2,2'-dipyridyl (200 mM). C Same as in B but with DmdR purified from R. fascians. Lanes 1, labeled desA; 2, labeled desA with DmdR; 3, labeled desA with DmdR and excess unlabeled desA.