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Fangying Song, Ning Liu, Minghao Liu, Yihua Chen, Ying Huang
Mycemycins A-E are new members of the dibenzoxazepinone (DBP) family, derived from the gntR gene-disrupted deep sea strain Streptomyces olivaceus FXJ8.012Δ1741 and the soil strain Streptomyces sp. FXJ1.235. In this paper, we report the identification of the gene clusters and pathways' inference for mycemycin biosynthesis in the two strains. Bioinformatics analyses of the genome sequences of S. olivaceus FXJ8.012Δ1741 and S . sp. FXJ1.235 predicted two divergent mycemycin gene clusters, mym and mye , respectively...
March 20, 2018: Marine Drugs
Jia-Nan Wang, Hao-Jian Zhang, Jia-Qi Li, Wan-Jing Ding, Zhong-Jun Ma
Nine new indolocarbazoles (1-9) were isolated from the marine-derived Streptomyces sp. DT-A61. Among them compounds 1-8 featured a hydroxy group at the C-3 or C-9 position. All purified compounds were identified by 1D and 2D NMR and HRESIMS data. The absolute configurations of 4-6, 8, and 9 were determined by electronic circular dichroism spectroscopic data. Compound 7 exhibited significant activity against human prostate PC-3 cancer cells with an IC50 value of 0.16 μM. Compounds 1, 5, 6, and 9 showed moderate inhibition against the same cell line with IC50 values of 8...
March 20, 2018: Journal of Natural Products
Munhyung Bae, Jedo Oh, Eun Seo Bae, Joonseok Oh, Joonseong Hur, Young-Ger Suh, Sang Kook Lee, Jongheon Shin, Dong-Chan Oh
WS9326H (1), a new cyclic peptide, was isolated from a mudflat-derived Streptomyces strain. Based on analysis by 1D/2D NMR, UV spectroscopy, and mass spectrometry, compound 1 was determined to have the gross structure of a cyclic heptapeptide bearing an unprecedented pyrazolone ring connected to a d-arabinitol via an amide bond. The absolute configuration of 1 was established by multistep chemical derivatizations, comprehensive NMR, and LC/MS analyses of the derivatives and quantum mechanics-based computational methods...
March 20, 2018: Organic Letters
Min Wang, Dandan Chen, Qunfei Zhao, Wen Liu
The species Streptomyces lincolnensis is known as a producer of lincomycin A, a clinically important lincosamide antibiotic with activity against Gram-positive bacteria. Here, we report that S. lincolnensis produces a new cysteate-containing lactone product, cysteoamide (1), which arises from non-ribosomal peptide synthetase-programmed sequential assembly of the monomers phenylacetic acid, valine, cysteate, threonine, β-hydroxyleucine and β-alanine and subsequent intramolecular cyclization to form a lactone ring...
March 20, 2018: Journal of Organic Chemistry
Maria A Schumacher, Chris D den Hengst, Matthew J Bush, T B K Le, Ngat T Tran, Govind Chandra, Wenjie Zeng, Brady Travis, Richard G Brennan, Mark J Buttner
Streptomycetes are notable for their complex life cycle and production of most clinically important antibiotics. A key factor that controls entry into development and the onset of antibiotic production is the 68-residue protein, BldC. BldC is a putative DNA-binding protein related to MerR regulators, but lacks coiled-coil dimerization and effector-binding domains characteristic of classical MerR proteins. Hence, the molecular function of the protein has been unclear. Here we show that BldC is indeed a DNA-binding protein and controls a regulon that includes other key developmental regulators...
March 19, 2018: Nature Communications
Alejandro D Bolzán, Martha S Bianchi
Bleomycin (BLM) is an antibiotic isolated from Streptomyces verticillus. It has radiomimetic actions on DNA thus it has been widely used in clinical chemotherapy for the treatment of different types of cancer, including head and neck tumors, lymphomas, squamous-cell carcinomas and germ-cell tumors. Because of this, the study of BLM genotoxicity is of practical interest. This antibiotic is an S-independent clastogen and an agent that generates free radicals and induces single- and double-strand breaks in DNA...
January 2018: Mutation Research
Antonio Rizzo, Dirk Trauner
An approach toward (-)-enterocin, an antibiotic isolated from Streptomyces hygroscopicus, is described. Its compact, heavily oxidized protoadamantane core represents a daunting challenge for an efficient synthesis. Convergent assembly of its 2-oxabicyclo[3.3.1]nonane core with a cuprate-mediated Barbier reaction is disclosed. Its functionalization to a suitable substrate for a biomimetic aldol to close the final ring of the natural product is evaluated.
March 19, 2018: Organic Letters
Yanlong Yang, Yuting Zhang, Shasha Zhang, Qingwen Chen, Ke Ma, Li Bao, Yong Tao, Wenbing Yin, Guodong Wang, Hongwei Liu
Sesterterpenes are usually found in plants and fungi, but are rare in bacteria. Here, we present the identification of StsC from Streptomyces somaliensis, a member of the UbiA superfamily, as a membrane-bound sesterterpene cyclase in bacteria. The cyclized products for StsC, somaliensenes A (1) and B (2), were identified by expressing the corresponding gene in an engineered Escherichia coli strain. The structures of 1 and 2 were determined by analysis of the NMR and MS spectroscopic data.
March 19, 2018: Journal of Natural Products
Zheng Cui, Xiachang Wang, Stefan Koppermann, Jon S Thorson, Christian Ducho, Steven G Van Lanen
Muraymycins are nucleoside antibiotics isolated from Streptomyces sp. NRRL 30471 and several mutant strains thereof that were generated by random, chemical mutagenesis. Reinvestigation of two mutant strains using new media conditions led to the isolation of three new muraymycin congeners, named B8, B9, and C6 (1-3), as well as a known muraymycin, C1. Structures of the compounds were elucidated by HRMS and 1D and 2D NMR spectroscopic analyses. Complete 2D NMR assignments for the known muraymycin C1 are also provided for the first time...
March 19, 2018: Journal of Natural Products
Anna J Komor, Andrew J Jasniewski, Lawrence Que, John D Lipscomb
Covering: up to 2017The participation of non-heme dinuclear iron cluster-containing monooxygenases in natural product biosynthetic pathways has been recognized only recently. At present, two families have been discovered. The archetypal member of the first family, CmlA, catalyzes β-hydroxylation of l-p-aminophenylalanine (l-PAPA) covalently linked to the nonribosomal peptide synthetase (NRPS) CmlP, thereby effecting the first step in the biosynthesis of chloramphenicol by Streptomyces venezuelae. CmlA houses the diiron cluster in a metallo-β-lactamase protein fold instead of the 4-helix bundle fold of nearly every other diiron monooxygenase...
March 19, 2018: Natural Product Reports
Pin Yu, Qing-Ting Bu, Yi-Li Tang, Xu-Ming Mao, Yong-Quan Li
AdpA, an AraC/XylS family protein, had been proved as a key regulator for secondary metabolism and morphological differentiation in Streptomyces griseus . Here, we identify AdpAch , an ortholog of AdpA, as a "higher level" pleiotropic regulator of natamycin biosynthesis with bidirectional regulatory ability in Streptomyces chattanoogensis L10. DNase I footprinting revealed six AdpAch -binding sites in the scnRI - scnRII intergenic region. Further analysis using the xylE reporter gene fused to the scnRI - scnRII intergenic region of mutated binding sites demonstrated that the expression of scnRI and scnRII was under the control of AdpAch ...
2018: Frontiers in Microbiology
Margherita Sosio, Eleonora Gaspari, Marianna Iorio, Silvia Pessina, Marnix H Medema, Alice Bernasconi, Matteo Simone, Sonia I Maffioli, Richard H Ebright, Stefano Donadio
Pseudouridimycin (PUM) is a selective nucleoside-analog inhibitor of bacterial RNA polymerase with activity against Gram-positive and Gram-negative bacteria. PUM, produced by Streptomyces sp. ID38640, consists of a formamidinylated, N-hydroxylated Gly-Gln dipeptide conjugated to 5'-aminopseudouridine. We report the characterization of the PUM gene cluster. Bioinformatic analysis and mutational knockouts of pum genes with analysis of accumulated intermediates, define the PUM biosynthetic pathway. The work provides the first biosynthetic pathway of a C-nucleoside antibiotic and reveals three unexpected features: production of free pseudouridine by the dedicated pseudouridine synthase, PumJ; nucleoside activation by specialized oxidoreductases and aminotransferases; and peptide-bond formation by amide ligases...
February 26, 2018: Cell Chemical Biology
Dandan Han, Lanying Wang, Yanping Luo
Actinomycetes are an important group of gram-positive bacteria that play an essential role in the rhizosphere ecosystem. The confrontation culture and Oxford cup method were used to evaluate the antagonistic activities of strains, which were isolated from the rhizosphere soil of Mikania micrantha. The two isolates were identified using morphological and physiological tests combined with 16S rRNA-based molecular analysis, respectively. The type I polyketone synthase (PKS-I) was amplified. The constituents of fermentation metabolites were analyzed by gas chromatography mass spectrometry...
March 2018: Microbiological Research
Bingbing Hou, Liyuan Tao, Xiaoyu Zhu, Wei Wu, Meijin Guo, Jiang Ye, Haizhen Wu, Huizhan Zhang
Global regulator BldA, the only tRNA for a rare leucine codon UUA, is best known for its ability to affect morphological differentiation and secondary metabolism in the genus Streptomyces. In this study, we confirmed the regulatory function of the bldA gene (Genbank accession no. EU124663.1) in Streptomyces lincolnensis. Disruption of bldA hinders the sporulation and lincomycin production, that can recur when complemented with a functional bldA gene. Western blotting assays demonstrate that translation of the lmbB2 gene which encodes a L-tyrosine hydroxylase is absolutely dependent on BldA; however, mistranslation of the lmbU gene which encodes a cluster-situated regulator (CSR) is observed in a bldA mutant...
March 17, 2018: Applied Microbiology and Biotechnology
Christian Greunke, Elke Regina Duell, Paul Michael D'Agostino, Anna Glöckle, Katharina Lamm, Tobias Alexander Marius Gulder
Specialized metabolites from bacteria are an important source of inspiration for drug development. The genes required for the biosynthesis of such metabolites in bacteria are usually organized in so-called biosynthetic gene clusters (BGCs). Using modern bioinformatic tools, the wealth of genomic data can be scanned for such BGCs and the expected products can often structurally be predicted in silico. This facilitates the directed discovery of putatively novel bacterial metabolites. However, the production of these molecules often requires genetic manipulation of the BGC for activation or the expression of the pathway in a heterologous host...
March 13, 2018: Metabolic Engineering
Alma Botas, Rosario Pérez-Redondo, Antonio Rodríguez-García, Rubén Álvarez-Álvarez, Paula Yagüe, Angel Manteca, Paloma Liras
ArgR is a well-characterized transcriptional repressor controlling the expression of arginine and pyrimidine biosynthetic genes in bacteria. In this work, the biological role of Streptomyces coelicolor ArgR was analyzed by comparing the transcriptomes of S. coelicolor Δ argR and its parental strain, S. coelicolor M145, at five different times over a 66-h period. The effect of S. coelicolor ArgR was more widespread than that of the orthologous protein of Escherichia coli , affecting the expression of 1544 genes along the microarray time series...
2018: Frontiers in Microbiology
Konstantinos C Tsolis, Evridiki-Pandora Tsare, Georgia Orfanoudaki, Tobias Busche, Katerina Kanaki, Reshmi Ramakrishnan, Frederic Rousseau, Joost Schymkowitz, Christian Rückert, Jörn Kalinowski, Jozef Anné, Spyridoula Karamanou, Maria I Klapa, Anastassios Economou
BACKGROUND: Members of the genus Streptomyces are Gram-positive bacteria that are used as important cell factories to produce secondary metabolites and secrete heterologous proteins. They possess some of the largest bacterial genomes and thus proteomes. Understanding their complex proteomes and metabolic regulation will improve any genetic engineering approach. RESULTS: Here, we performed a comprehensive annotation of the subcellular localization of the proteome of Streptomyces lividans TK24 and developed the Subcellular Topology of Polypeptides in Streptomyces database (SToPSdb) to make this information widely accessible...
March 15, 2018: Microbial Cell Factories
Miguel R Lugo, Bronwyn Lyons, Cristina Lento, Derek J Wilson, A Rod Merrill
Scabin is a mono-ADP-ribosyltransferase enzyme and is a putative virulence factor produced by the plant pathogen, Streptomyces scabies. Previously, crystal structures of Scabin were solved in the presence and absence of substrate analogues and inhibitors. Herein, experimental (hydrogen-deuterium exchange), simulated (molecular dynamics), and theoretical (Gaussian Network Modeling) approaches were systematically applied to study the dynamics of apo-Scabin in the context of a Scabin·NAD+·DNA model. MD simulations revealed that the apo-Scabin solution conformation correlates well with the X-ray crystal structure, beyond the conformation of the exposed, mobile regions...
2018: PloS One
Youfa Luo, Yonggui Wu, Hu Wang, Rongrong Xing, Zhilin Zheng, Jing Qiu, Lian Yang
This comparative field study examined the responses of bacterial community structure and diversity to the revegetation of zinc (Zn) smelting waste slag with eight plant species after 5 years. The microbial community structure of waste slag with and without vegetation was evaluated using high-throughput sequencing. The physiochemical properties of Zn smelting slag after revegetation with eight plant rhizospheres for 5 years were improved compared to those of bulk slag. Revegetation significantly increased the microbial community diversity in plant rhizospheres, and at the phylum level, Proteobacteria, Acidobacteria, and Bacteroidetes were notably more abundant in rhizosphere slags than those in bulk waste slag...
March 14, 2018: Environmental Science and Pollution Research International
Michelle N Goettge, Joel P Cioni, Kou-San Ju, Katharina Pallitsch, William W Metcalf
Several oxime-containing small molecules have useful properties, including antimicrobial, insecticidal, anticancer, and immunosuppressive activities. Phosphonocystoximate and its hydroxylated congener, hydroxyphosphonocystoximate, are recently discovered oxime-containing natural products produced by Streptomyces sp. NRRL S-481 and Streptomyces regensis NRRL WC-3744, respectively. The biosynthetic pathways for these two compounds are proposed to diverge at an early step in which 2-aminoethylphosphonate (2AEPn) is converted to (S)-1-hydroxy-2- aminoethylphosphonate ((S)-1H2AEPn) in S...
March 14, 2018: Journal of Biological Chemistry
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