Project description:Microbial-derived natural products are important in both the pharmaceutical industry and academic research. As the metabolic potential of original producer especially Streptomyces is often limited by slow growth rate, complicated cultivation profile, and unfeasible genetic manipulation, so exploring a Streptomyces as a super industrial chassis is valuable and urgent. Streptomyces sp. FR-008 is a fast-growing microorganism and can also produce a considerable amount of macrolide candicidin via modular polyketide synthase. In this study, we evaluated Streptomyces sp. FR-008 as a potential industrial-production chassis. First, PacBio sequencing and transcriptome analyses indicated that the Streptomyces sp. FR-008 genome size is 7.26 Mb, which represents one of the smallest of currently sequenced Streptomyces genomes. In addition, we simplified the conjugation procedure without heat-shock and pre-germination treatments but with high conjugation efficiency, suggesting it is inherently capable of accepting heterologous DNA. In addition, a series of promoters selected from literatures was assessed based on GusA activity in Streptomyces sp. FR-008. Compared with the common used promoter ermE*-p, the strength of these promoters comprise a library with a constitutive range of 60-860%, thus providing the useful regulatory elements for future genetic engineering purpose. In order to minimum the genome, we also target deleted three endogenous polyketide synthase (PKS) gene clusters to generate a mutant LQ3. LQ3 is thus an "updated" version of Streptomyces sp. FR-008, producing fewer secondary metabolites profiles than Streptomyces sp. FR-008. We believe this work could facilitate further development of Streptomyces sp. FR-008 for use in biotechnological applications.
Project description:Gene fscTE, encoding a putative type II thioesterase (TEII), was associated with the FR-008/candicidin gene cluster. Deletion of fscTE reduced approximately 90% of the FR-008/candicidin production, while the production level was well restored when fscTE was added back to the mutant in trans. FscTE was unable to compensate for the release of the maturely elongated polyketide as site-directed inactivation of the type I thioesterase (TEI) totally abolished FR-008/candicidin production. Direct biochemical analysis of FscTE in parallel with its homologue TylO from the tylosin biosynthetic pathway demonstrated their remarkable preferences for acyl-thioesters (i.e., propionyl-S-N-acetylcysteamine [SNAC] over methylmalonyl-SNAC and acetyl-SNAC over malonyl-SNAC) and thus concluded that TEII could maintain effective polyketide biosynthesis by selectively removing the nonelongatable residues bound to acyl carrier proteins. Overexpression of FscTE under the strong constitutive ermE*p promoter in the wild-type strain did not suppress FR-008/candicidin formation, which confirmed its substrate specificity in vivo. Furthermore, successful complementation of the fscTE mutant was obtained with fscTE and tylO, whereas no complementation was detected with nonribosomal peptide synthetase (NRPS) TEII tycF and srfAD, reflecting substrate specificities of TEIIs distinctive from those of either polyketide synthases or NRPSs.
Project description:In the arsenic resistance gene cluster from the large linear plasmid pHZ227, two novel genes, arsO (for a putative flavin-binding monooxygenase) and arsT (for a putative thioredoxin reductase), were coactivated and cotranscribed with arsR1-arsB and arsC, respectively. Deletion of the ars gene cluster on pHZ227 in Streptomyces sp. strain FR-008 resulted in sensitivity to arsenic, and heterologous expression of the ars gene cluster in the arsenic-sensitive Streptomyces strains conferred resistance on the new hosts. The pHZ227 ArsB protein showed homology to the yeast arsenite transporter Acr3p. The pHZ227 ArsC appears to be a bacterial thioredoxin-dependent ArsC-type arsenate reductase with four conserved cysteine thioredoxin-requiring motifs.
Project description:Streptomyces sp. MB42 produces antimicrobial compound under the pressence of specific compounds. This experiment is to see which gene cluster upregulated during the treatment of target compound.
Project description:Streptomyces sp. M7 has demonstrated ability to remove lindane from culture media and soils. In this study, we used MS-based label-free quantitative proteomic to understand lindane degradation and its metabolic context in Streptomyces sp. M7. We identified the proteins involved in the up-stream degradation pathway. Our results demonstrated that mineralization of lindane is feasible since proteins from an unusual down-stream degradation pathway were also identified. Degradative steps were supported by an active catabolism that supplied energy and reducing equivalents in the form of NADPH. This is the first study in which degradation steps of an organochlorine compound and metabolic context are elucidate in a biotechnological genus as Streptomyces. These results serve as basement to study other degradative actinobacteria and to improve the degradation processes of Streptomyces sp. M7.
Project description:This study aimed to investigate the variations in the protein composition of Streptomyces sp. PU10 when cultivated with either Impranil (polyestere-polyurethane) or glucose as the carbon source. We analyzed both the intracellular and extracellular protein fractions to gain insights into the intricate processes involving PU degradation, intermediate metabolic pathways in PU degradation, and the connection between primary and secondary metabolism within Streptomyces sp. PU10.
Project description:The Myc/Max heterodimer has crucial roles in normal cellular processes such as cell proliferation, metabolism, apoptosis, and differentiation, but its activity is often deregulated in a majority of human cancers. In an effort to explore alternative modes of Myc perturbation, we identified KI-MS2-008 as a small molecule that binds Max and modulates Myc-driven transcription, and in some cellular contexts, KI-MS2-008 treatment leads to a decrease in c-Myc protein levels. As the Myc/Max heterodimer controls many cellular processes, we expected that treatment with this small molecule would cause changes in the transcriptome. We found that treatment with 10 µM KI-MS2-008 resulted in global alterations in the transcriptome, mimicking direct Myc inactivation with doxycycline in P493-6, a B cell line with a Tet-Off system for c-Myc expression. We also discovered enrichment of various Myc target gene sets in the genes downregulated in response to KI-MS2-008 treatment in P493-6 cells. This trend was also observed in ST486 cells, but not in P3HR1 cells, which were chosen as non-engineered B cell lines that were sensitive and insensitive, respectively, toward KI-MS2-008 in cell viability assays.