Project description:In this work, we identified glucose and glycerol as tacrolimus repressing carbon sources in the important species Streptomyces tsukubaensis. A genome-wide analysis of the transcriptomic response to glucose and glycerol additions was performed using microarray technology. The transcriptional time series obtained allowed us to compare the transcriptomic profiling of S. tsukubaensis growing under tacrolimus producing and non-producing conditions. The analysis revealed important and different metabolic changes after the additions and a lack of transcriptional activation of the fkb cluster. In addition, we detected important differences in the transcriptional response to glucose between S. tsukubaensis and the model species Streptomyces coelicolor. A number of genes encoding key players of morphological and biochemical differentiation were strongly and permanently downregulated by the carbon sources. Finally, we identified several genes showing transcriptional profiles highly correlated to that of the tacrolimus biosynthetic pathway regulator FkbN that might be potential candidates for the improvement of tacrolimus production
Project description:FK506 (tacrolimus) is a valuable immunosuppressant produced by several Streptomyces strains. In the genome of the wild type producer Streptomyces tsukubaensis NRRL18488 FK506 biosynthesis is encoded by a gene cluster that spans 83.5 kilobases. A whole transcriptome differential shotgun sequencing of S. tsukubaensis was performed to analyze transcription at two different time points; before and during active FK506 production. In total 8,914 transcription start sites were identified in either condition, which enabled precise determination of the 5'-UTR length of the corresponding transcripts as well as the identification of two consensus sequence motifs in the promoter regions. The transcription start sites of all gene operons within the FK506 cluster were identified, including three examples of leaderless RNA transcripts. These data provide detailed insight into the transcription of the FK506 biosynthetic gene cluster and supports future regulatory studies and genetic manipulations.
Project description:Ribosome pausing at the AT-rich codons regulates the protein expression of secondary metabolite gene clusters in the Streptomyces tsukubaensis NRRL 18488
Project description:RNA-seq Transcriptional Profiling of the FK506 Biosynthetic Gene Cluster in Streptomyces tsukubaensis NRRL18488 and General Analysis of the Transcriptome
Project description:Chitin is the second most abundant biopolymer present in soils and is utilized by antibiotic-producing Streptomyces species. Its monomer, N-acetylglucosamine (NAG), regulates the developmental program of the model organism Streptomyces coelicolor. NAG blocks differentiation when growing on rich medium whilst it promotes development on poor culture media. We report here the negative effect of NAG on tacrolimus (FK506) production in Streptomyces tsukubaensis NRRL 18488 growing on a defined rich medium. Using microarrays technology, we found that GlcNAc represses the transcription of fkbN, encoding the main transcriptional activator of the tacrolimus biosynthetic cluster, and of ppt1, encoding a phosphopantheteinyltransferase involved in tacrolimus biosynthesis. On the contrary, NAG stimulated transcription of genes related to amino acid and nucleotide biosynthesis, DNA replication, RNA translation, glycolysis, pyruvate metabolism, and key gene members of the PHO regulon. The results obtained support those previously reported for S. coelicolor, but some important differences were observed
