Streptomyces coelicolor M600 BldD ChIP-chip comparison of wild-type with bldD null mutant

BldD is a transcriptional regulator essential for morphological development and antibiotic production in Streptomyces coelicolor. Here we identify the BldD regulon by means of chromatin immunoprecipitation. The BldD regulon encompasses ~167 transcriptional units, of which more than 20 are known to play important roles in development and/or secondary metabolism. Strikingly, 42 BldD target genes (~25% of the regulon) encode regulatory proteins, stressing the central, pleiotropic role of BldD. Almost all BldD-binding sites identified by ChIP-chip are present in the promoters of the target genes. An exception is the tRNA gene bldA, where BldD binds within the region encoding the primary transcript, immediately downstream of the position corresponding to the processed, mature 3′-end of the tRNA. We identified a novel BldD target gene (cdgA) that influences differentiation and antibiotic production. cdgA encodes a GGDEF domain protein, implicating c-di-GMP in the regulation of Streptomyces development. ChIP-chip exp comparing IP with BldD antibody against total DNA control in wild-type strain vs bldD mutant strain. Wild-type strain was analysed in triplicate