DNA-binding specificity of AdpA, a transcriptional activator in the A-factor regulatory cascade in Streptomyces griseus.

摘要: Summary AdpA, belonging to the AraC/XylS family, is key transcriptional activator for a number of genes various functions in A-factor regulatory cascade Streptomyces griseus. It consists ThiJ/PfpI/DJ-1-like dimerization domain at its N-terminal portion and DNA-binding with two helix–turn–helix motifs C-terminal portion, representing large subgroup family. Uracil interference assay missing T GA assays on several AdpA binding sites, followed by gel mobility shift systematically mutated revealed consensus AdpA-binding sequence, 5′-TGGCSNGWWY-3′ (S: G or C; W: A T; Y: N: any nucleotide). dimer bound site including sequences, space 13–14 bp, as an inverted repeat (type I) positions, example more than 200 bp upstream (−200) 25 bp downstream (+25) from start point target gene. In addition, also sequence single copy II) most cases, −40 −50 −60. For activation, some required simultaneous type I II but others only site. sites distances between sequences significant affinities, although optimal bind were 13–14 bp 2 bp. The therefore connected flexible linker. specificity conjunction that other family members discussed.