ABSTRACT: Characterization of a pleiotropic regulator MtrA in Streptomyces avermitilis controlling avermectin production and morphological differentiation
Project description:Investigation of whole genome gene expression level changes in Streptomyces avermitilis delta-aveI mutant, compared to the wild-type strain. The mutants analyzed in this study are further described in Chen L, Lu Y., Chen J, Zhang W, Shu D, Qin Z, Yang S, Jiang W. (2008) Characterization of a negative regulator AveI for avermectin biosynthesis in Streptomyces avermitilis NRRL8165. Appl Microbiol Biotechnol 80(2): 277-86.
Project description:Investigation of whole genome gene expression level changes in Streptomyces avermitilis delta-aveI mutant, compared to the wild-type strain. The mutants analyzed in this study are further described in Chen L, Lu Y., Chen J, Zhang W, Shu D, Qin Z, Yang S, Jiang W. (2008) Characterization of a negative regulator AveI for avermectin biosynthesis in Streptomyces avermitilis NRRL8165. Appl Microbiol Biotechnol 80(2): 277-86. A six chip study using total RNA recovered from three separate Streptomyces avermitilis NRRL8165 and three separate cultures of a Streptomyces avermitilis NRRL8165 delta-aveI (delta-l) mutant. 3 separate RMA normalizations performed, one for each pair of control and mutant samples.
Project description:Streptomyces avermitilis is a avermectin producer.Since the avermectin biosynthesis rate has a increased significantly in P3 fermentation stage( P1,24–96 h; P2:96–192 h, P3:192–240 h), but the sugar absorption rate decreased significantly in P3 fermentation stage, in order to improve the titer of avermectins, we conducted transcriptomic analysis of Streptomyces avermitilis S0 in fourth and eighth day, and selected native promoters with appropriate temple using to express sugar transporters.
Project description:The developmental life cycle of Streptomyces species includes aerial hyphae formation and spore maturation, two distinct developmental processes that are controlled, respectively, by two families of developmental regulatory genes, bld and whi. In this study, we show that the response regulator MtrA (SCO3013) is critical for normal development of aerial hyphae in S. coelicolor and related species. ΔmtrA, a deletion mutant of the response regulator gene mtrA, exhibited the bald phenotype typical of bld mutants defective in aerial mycelium formation, with formation either much delayed or absent depending on the culture medium. Transcriptional analysis indicated that MtrA activates multiple genes involved in formation of aerial mycelium, including chp, rdl, and ram genes, as well as developmental regulatory genes of the bld and whi families. However, the major regulatory gene bldD showed enhanced expression in ΔmtrA, suggesting it is repressed by MtrA. EMSAs indicated that MtrA binds upstream of several genes with altered expression in ΔmtrA, including bldD and whiI, and sequences similar to the consensus binding sequence for MtrA of another actinomycete, Mycobacterium tuberculosis, were found in the bound sites. A loosely conserved recognition sequence containing two short, direct repeats was identified for MtrA of S. coelicolor and was validated using mutational analysis. MtrA homologues are widely distributed among Streptomyces species, and as with S. coelicolor, deletion of the mtrA homologues sve_2757 from S. venezuelae and sli_3357 from S. lividans resulted in conditional bald morphology. Our study suggests a critical and conserved role for MtrA in Streptomyces development.
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.
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. ChIP-chip experiment using an anti-BldC antibody and a total DNA control. Comparison of IP in wild-type strain vs. IP in a bldC null mutant strain.
Project description:PAS-LuxR transcriptional regulators are highly conserved enzymes governing polyene macrolide antifungal biosynthesis. One of such regulators PteF, is located in the polyene macrolide filipin gene cluster from Streptomyces avermitilis and its mutation leads to a drastic decrease in filipin production as well as a severe loss of oligomycin production, an ATP-synthase inhibitor of macrolide structure, and a delay in sporulation. This transcriptomic study aims to understand the regulatory role of PteF and unveil the reach of PAS-LuxR transcriptional regulators in the global metabolism of Streptomyces.
Project description:This SuperSeries is composed of the following subset Series: GSE33992: Streptomyces griseus transcriptome analysis in solid culture with delta adpA, encoding a global transcriptional regulator involved in morphological differentiation and secondary metabolism GSE33993: Streptomyces griseus transcriptome analysis in liquid culture with delta adpA, encoding a global transcriptional regulator involved in morphological differentiation and secondary metabolism GSE34036: Genome-wide distribution of AdpA, a global regulator for secondary metabolism and morphological differentiation in Streptomyces [liquid] GSE34037: Genome-wide distribution of AdpA, a global regulator for secondary metabolism and morphological differentiation in Streptomyces [solid] Refer to individual Series
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:The gram-positive bacterium, Streptomyces avermitilis holds industrial importance, which produces widely used anthelmintic agent, avermectin. Furthermore, S. avermitilis is generally considered as a prominent heterologous gene expression host for diverse secondary metabolites biosynthesis. However, despite of its industrial importance, it largely remains unknown how its genome is organized and regulated for timely gene expression. Here, we determined 1,601 transcription units (TU) encoded in its genome using the integrated analysis of high-throughput sequencing data including dRNA-Seq, Term-Seq, RNA-Seq, and Ribo-Seq. In addition to TU cataloguing, these information-rich results also revealed the presence of diverse regulatory elements for the transcriptional and translational control of individual TU, such as promoters, 5¢-UTRs, terminators, 3¢-UTRs, and riboswitches. The conserved promoter sequences for transcription initiation were identified from 2,361 transcription start sites as 5¢-TANNNT and 5¢-TGAC for -10 and -35 elements, respectively. Interestingly, the -35 element and spacer length between them were critical for transcriptional regulation of functionally distinct genes. Total 2,017 transcription termination sites were detected from Term-Seq analysis, revealing that stem structure formation is a prerequisite for transcription termination and that Rho-independent termination prevails in S. avermitilis. Lastly, the TU architecture suggests the presence of novel small RNAs and cis-regulatory elements in the genome. Our findings will serve as invaluable resources for comprehensive understanding on regulatory features of S. avermitilis. Moreover, it is anticipated the elevation of its potential as the heterologous expression host for diverse secondary metabolite biosynthesis.