Project description:We have integrated nucleotide resolution genome-scale measurements of the transcriptome and translatome of the Streptomyces coelicolor A3(2), the model antibiotic-producing actinomycete. Our systematic study determined 3,473 transcription start sites, leading to discovery of a high proportion (~21%) of leaderless mRNAs and 230 non-coding RNAs; this enabled deduction of promoter architecture on a genome-scale. Ribosome profiling analysis revealed that the translation efficiency was negatively correlated for secondary metabolic genes. These results provide novel fundamental insights into translational regulation of secondary metabolism that enables rational synthetic biology approaches to awaken such ‘silent’ secondary metabolic pathways.
Project description:Background: During the lifetime of a fermenter culture, the soil bacterium S. coelicolor undergoes a major metabolic switch from exponential growth to antibiotic production. We have studied gene expression patterns during this switch, using a specifically designed Affymetrix genechip and a high-resolution time-series of fermenter-grown samples. Results: Surprisingly, we find that the metabolic switch actually consists of multiple finely orchestrated switching events. Strongly coherent clusters of genes show drastic changes in gene expression already many hours before the classically defined transition phase where the switch from primary to secondary metabolism was expected. The main switch in gene expression takes only 2 hours, and changes in antibiotic biosynthesis genes are delayed relative to the metabolic rearrangements. Furthermore, global variation in morphogenesis genes indicates an involvement of cell differentiation pathways in the decision phase leading up to the commitment to antibiotic biosynthesis. Conclusions: Our study provides the first detailed insights into the complex sequence of early regulatory events during and preceding the major metabolic switch in S. coelicolor, which will form the starting point for future attempts at engineering antibiotic production in a biotechnological setting. Keywords: time course
Project description:We have integrated nucleotide resolution genome-scale measurements of the transcriptome and translatome of the Streptomyces coelicolor A3(2), the model antibiotic-producing actinomycete. Our systematic study determined 3,473 transcription start sites, leading to discovery of a high proportion (~21%) of leaderless mRNAs and 230 non-coding RNAs; this enabled deduction of promoter architecture on a genome-scale. Ribosome profiling analysis revealed that the translation efficiency was negatively correlated for secondary metabolic genes. These results provide novel fundamental insights into translational regulation of secondary metabolism that enables rational synthetic biology approaches to awaken such âsilentâ secondary metabolic pathways. Profiles of primary transcripts, whole transcripts, and ribosome protected fragments (RPFs) of Streptomyces coelicolor were generated by deep sequencing using Illumina Miseq.
Project description:To help understand the functions of GBL receptor ScbR and antibiotic receptor ScbR2, the global transcriptional profiles of scbRDM and scbR2DM compared to WT were studied.
Project description: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.
Project description:Background: During the lifetime of a fermenter culture, the soil bacterium S. coelicolor undergoes a major metabolic switch from exponential growth to antibiotic production. We have studied gene expression patterns during this switch, using a specifically designed Affymetrix genechip and a high-resolution time-series of fermenter-grown samples. Results: Surprisingly, we find that the metabolic switch actually consists of multiple finely orchestrated switching events. Strongly coherent clusters of genes show drastic changes in gene expression already many hours before the classically defined transition phase where the switch from primary to secondary metabolism was expected. The main switch in gene expression takes only 2 hours, and changes in antibiotic biosynthesis genes are delayed relative to the metabolic rearrangements. Furthermore, global variation in morphogenesis genes indicates an involvement of cell differentiation pathways in the decision phase leading up to the commitment to antibiotic biosynthesis. Conclusions: Our study provides the first detailed insights into the complex sequence of early regulatory events during and preceding the major metabolic switch in S. coelicolor, which will form the starting point for future attempts at engineering antibiotic production in a biotechnological setting. Keywords: time course F199: 32 samples, no replicates; one hour resolution from 20-44h; two hour resolution 44-60h; sample missing for 25h F201: 8 samples, no replicates; four hour resolution from 24-48h; one sample at 60h F202: 15 samples, no replicates; four hour resolution from 24-32h; one hour resolution from 34-40h; two hour resolution from 42-48h; one sample at 60h SysMO STREAM Consortium
Project description:We report 6 genes that were found to be regulated by SoxR in stationary phase when the bacteria produce the antibiotic actinorhodin. Five of these genes are previously confirmed SoxR targets; the sixth is a novel SoxR-target.
Project description:Global regulation by the Streptomyces coelicolor atypical MerR-like transcription factor BldC. BldC is a transcriptional regulator essential for morphological development and antibiotic production in Streptomyces coelicolor. Here we identify the BldC regulon by means of chromatin immunoprecipitation (ChIP) microarray analysis. The BldC regulon encompasses at least 201 transcriptional units, which include many genes that play key roles in Streptomyces development (e.g., bldC itself, bldB, bldM, whiB, whiD, whiI, sigF, smeA-sffA, hupS), antibiotic production (e.g., afsK) and stress response (e.g., clpB, nsrR, sigE, sigF). All BldC-binding sites identified by ChIP-chip are present in the promoters of the target genes. In vitro DNA-binding experiments show that BldC is capable of binding DNA specifically in the absence of other proteins and suggest that BldC is a minor-groove DNA-binding protein. The regulon of BldC partially overlaps with that of the pleiotropic regulator BldD. BldC and BldD bind to distinct sites in the promoter region of smeA, where they simultaneously repress its transcription.