The ever-increasing bacterial genomic repositories reveal a great number of uncharacterized biosynthetic gene clusters, representing a tremendous resource for natural product discovery. Genome mining of the marine sp. NA03103 indicates the presence of an orphan nonribosomal peptide synthetase (NRPS) gene cluster (), to which there are no homologous gene clusters in the public genome databases. Heterologous expression of the gene cluster in the SBT18 strain led to the discovery of two novel cyclopeptides, ashimides A and B ( and ), with showing cytotoxic activity. In addition, we use bioinformatic analysis, gene inactivation and stable isotope labelling experiments, as well as biochemical assays, to present a coherent and novel assembly line for ashimide biosynthesis, featuring an unusual desaturation, halogenation and cyclization cascade catalyzed by a P450 monooxygenase and a FAD-dependent halogenase.
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http://dx.doi.org/10.1039/c8sc05670f | DOI Listing |
Biochem Biophys Rep
March 2025
Department of Genetics and Molecular Biology, Faculty of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
Introduction: Gastric cancer (GC) is among the deadliest malignancies globally, characterized by hypoxia-driven pathways that promote cancer progression, including stemness mechanisms facilitating invasion and metastasis. This study aimed to develop a prognostic decision tree using genes implicated in hypoxia and stemness pathways to predict outcomes in GC patients.
Materials And Methods: GC RNA-seq data from The Cancer Genome Atlas (TCGA) were analyzed to compute hypoxia and stemness scores using Gene Set Variation Analysis (GSVA) and the mRNA expression-based stemness index (mRNAsi).
Org Biomol Chem
January 2025
State Key Laboratory of Chemical Biology, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China.
A lasso peptide biosynthetic gene cluster (BGC) was identified through genome mining in the species CGMCC 4.1857, which was isolated from acidic rhizosphere soil. The BGC was reconstructed in , leading to the heterologous production of a lasso peptide named streptacidin.
View Article and Find Full Text PDFAMB Express
January 2025
Department of Microbiology and Immunology, Faculty of Pharmacy, Ain Shams University, Cairo, 11566, Egypt.
In this study, Allium sativum, garlic, was selected to isolate endophytic bacteria and to evaluate the antimicrobial, antiviral, antioxidant, and cytotoxic activities of their produced metabolites followed by identification of the biosynthetic gene cluster of the antimicrobial metabolites using Oxford Nanopore Technology (ONT). Two bacterial isolates, C6 and C11, were found to have a broad-spectrum antagonistic effect against four standard microbial strains and were molecularly identified using 16 S ribosomal RNA sequence analysis and deposited in a local culture collection as B. velezensis CCASU-C6, and B.
View Article and Find Full Text PDFMycopathologia
January 2025
Teikyo University Institute of Medical Mycology (TIMM), 359 Otsuka, Hachioji, Tokyo, 192-0395, Japan.
We describe a novel Malassezia species named Malassezia polysorbatinonusus, isolated from a Japanese patient with seborrheic dermatitis. The internal transcribed spacer (ITS) region of the isolate (LSEM 4845) were only 94.7% identical to those of M.
View Article and Find Full Text PDFCommun Chem
January 2025
Graduate School of Engineering, Hokkaido University, N13-W8, Kita-ku, Sapporo, Hokkaido, 060-8628, Japan.
Lactacystin is an irreversible proteasome inhibitor isolated from Streptomyces lactacystinicus. Despite its importance for its biological activity, the biosynthesis of lactacystin remains unknown. In this study, we identified the lactacystin biosynthetic gene cluster by gene disruption and heterologous expression experiments.
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