Project description:The aim of this experiment was to map the transcription start sites (TSSs) in the bottromycin biosynthetic gene cluster from Streptomyces scabies, qualitatively assess the expression levels of this cluster within the bacterium's transcriptome and evaluate whether deletion of a potential regulatory gene in the cluster, btmL affects gene cluster expression.
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:We provide a manually-curated genome mining analysis of the bacterial plant pathogen Streptomyces scabiei. The expression of the deduced biosynthetic gene clusters was assessed by a RNAseq approach, and their potential to be induced by the virulence elicitors cellobiose and cellotriose was estimated by comparing mRNA levels before and after elicitor addition. Finally, we performed metabolomic analyzes to evaluate how the production of known specialized metabolites responds to virulence elicitors, in correlation (or not) with the transcriptomic data
Project description:Streptomyces are among the most prolific bacterial producers of specialized metabolites, including antibiotics. The linear genome is partitioned into a central region harboring core genes and two extremities enriched in specialized metabolite biosynthetic gene clusters (SMBGCs). The molecular mechanisms governing structure and function of these compartmentalized genomes remain mostly unknown. Here we show that in exponential phase, chromosome structure correlates with genetics compartmentalization: conserved, large and highly transcribed genes form boundaries that segment the central part of the genome into domains, whereas the terminal ends are transcriptionally, largely quiescent compartments with different structural features. Onset of metabolic differentiation is accompanied by remodeling of chromosome architecture from an ‘open’ to a rather ‘closed’ conformation, in which the SMBGCs are expressed forming new boundaries. Altogether, our results reveal that S. ambofacien's linear chromosome is partitioned into structurally distinct entities, indicating a link between chromosome folding, gene expression and genome evolution
Project description:Streptomyces bacteria make diverse specialised metabolites that form the basis of ~55% of clinically used antibiotics. Despite this, only 3% of their encoded specialised metabolites have been matched to molecules and understanding how their biosynthesis is controlled is essential to fully exploit their potential. Here we use Streptomyces formicae and the formicamycin biosynthetic pathway as a model to understand the complex regulation of specialised metabolism. We analysed all three pathway-specific regulators and found that biosynthesis is subject to negative feedback and redox control via two MarR-family proteins while activation of the pathway is dependent on a cytoplasmic two-component system. Like many Streptomyces antibiotics, formicamycins are only produced in solid culture and biosynthesis is switched off in aerated liquid cultures. Here, we demonstrate that a redox-sensitive repressor named ForJ senses oxygen via a single cysteine residue that is required to repress formicamycin biosynthesis in liquid cultures.
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:To identify unique gene expression in higher antibiotics producing Streptomyces coelicolor strain, non-producer M1146 and the derivative strain M1146+ACT (M1146 with actinorhodin biosynthetic genes cluster) was choosen for comparative transcriptome analysis. The genes with different gene expression might be key genes important for antibiotics production.
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
Project description:Background Streptomyces are key contributors to soil microbiome function, known for their biosynthetic diversity. While advances in -omics technologies have improved our understanding of microbiome composition and metabolic potential, the mechanisms underpinning interspecies interactions remain poorly resolved. Here, we investigate the molecular basis of interactions among four sympatric Streptomyces soil microbiome isolates, focusing on phenotypic, metabolomic and transcriptomic responses. Results Co-culture experiments revealed that one isolate, strain A, exhibited pronounced phenotypic changes when grown alongside each of the other three strains. Untargeted metabolomics and RNA-seq analyses showed that strain A undergoes distinct metabolic and transcriptional shifts depending on its partner, with the strongest response elicited by strain C. Despite all four strains possessing a conserved desferrioxamine biosynthetic gene cluster, only strain C constitutively produced desferrioxamine B (DFO-B), a hydroxymate siderophore, indicating a role of iron bioavailability in the interaction. Supplementation with DFO-B or iron mimicked the growth stimulation of strain A observed in co-culture with strain C, and CRISPR base editing of desD in strain C abolished both DFO production and the phenotypic induction of strain A. However, transcriptomic profiles of strain A varied significantly depending on the partner strain, with distinct sets of biosynthetic gene clusters and metabolic pathways activated in response to strains B and C, suggesting additional cues beyond DFO-B. In contrast, strain D did not elicit growth stimulation in its partners, and itself showed downregulation of amino acid and carbon metabolism when co-cultured with strain C. These findings indicate that Streptomyces interactions are not only mediated by siderophore piracy but also involve complex, strain-specific molecular responses. Conclusions Our findings demonstrate that Streptomyces interactions are highly strain-specific and only partly mediated by siderophore piracy, with DFO-B acting as a potent interspecies cue. The divergent molecular responses to different partners suggest nuanced mechanisms of microbial sensing and competition. These insights advance our understanding of microbial crosstalk and highlight the ecological and evolutionary complexity of siderophore-mediated interactions. By integrating transcriptomics, metabolomics, and biochemical assays, we present a robust framework for dissecting microbial interactions, with implications for microbiome engineering and synthetic community design.