0000000000014074
AUTHOR
Charles J. Thompson
Broad Spectrum Thiopeptide Recognition Specificity of theStreptomyces lividans TipAL Protein and Its Role in Regulating Gene Expression
Microbial metabolites isolated in screening programs for their ability to activate transcription of the tipA promoter (ptipA) in Streptomyces lividans define a class of cyclic thiopeptide antibiotics having dehydroalanine side chains ("tails"). Here we show that such compounds of heterogeneous primary structure (representatives tested: thiostrepton, nosiheptide, berninamycin, promothiocin) are all recognized by TipAS and TipAL, two in-frame translation products of the tipA gene. The N-terminal helix-turn-helix DNA binding motif of TipAL is homologous to the MerR family of transcriptional activators, while the C terminus forms a novel ligand-binding domain. ptipA inducers formed irreversible…
Developmental control of the heat-shock stress regulon in Streptomyces coelicolor
In the differentiating eubacterium Streptomyces coelicolor, nutritional imbalances activate a developmental programme which involves the heat-shock stress regulon. In liquid batch cultures, the growth curve could be separated into four components: rapid growth 1 (RG1), transition (T), rapid growth 2 (RG2) and stationary (S). Patterns of gene expression in cultures subjected to heat shock in various phases were recorded on two-dimensional gels and analysed using advanced statistical methods. The responses of all heat-shock proteins (HSPs) were highly dependent upon the growth phase, thus demonstrating that the four phases of growth were physiologically distinct. For many HSPs, the levels of …