The biosynthetic gene cluster for the pluramycin-type antitumor antibiotic hedamycin has been cloned from Streptomyces griseoruber. Sequence analysis of the 45.6 kb region revealed a variety of unique features such as a fabH homolog (KSIII), an acyltransferase (AT) gene, a set of type I polyketide synthase (PKS) genes, and two putative C-glycosyltransferase genes. As the first report of the cloning of the biosynthetic gene cluster for the pluramycin antibiotics, this work suggests that the biosynthesis of pluramycins utilize an iterative type I PKS system for the generation of a novel starter unit that subsequently primes the type II PKS system. It also implicates the involvement of a second catalytic ketosynthase (KSIII) to regulate this unusual priming step. Gene disruption is used to confirm the importance of both type I and II PKS genes for the biosynthesis of hedamycin.
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http://dx.doi.org/10.1016/j.chembiol.2004.04.016 | DOI Listing |
FEBS Lett
January 2025
Department of Chemistry, Tokyo Institute of Technology (Institute of Science Tokyo), Japan.
Modular polyketide synthases (PKSs) are multi-domain enzymes involved in the biosynthesis of polyketide natural products. The dehydratase (DH) domain catalyzes the dehydration of the β-hydroxyacyl unit attached to the acyl carrier protein (ACP) domain in modular PKS. Although the DH domain likely recognizes the cognate ACP domain during the dehydration reaction, the molecular basis of DH-ACP interactions remains elusive.
View Article and Find Full Text PDFCommun Biol
January 2025
Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel.
Polyketide synthases (PKSs) are crucial multidomain enzymes in diverse natural product biosynthesis. Parrots use a type I PKS to produce a unique pigment called psittacofulvin in their feathers. In domesticated budgerigars and lovebirds, the same amino acid substitution (R644W) within malonyl/acetyltransferase (MAT) domain of this enzyme has been shown to cause the blue phenotype with no psittacofulvin pigmentation, proposing a strong evolutionary constraint on the mechanism.
View Article and Find Full Text PDFFront Parasitol
April 2024
Institut für Parasitologie, Biomedizinisches Forschungszentrum Seltersberg (BFS), Justus Liebig Universitaet Giessen, Giessen, Germany.
Introduction: Schistosomiasis has for many years relied on a single drug, praziquantel (PZQ) for treatment of the disease. Immense efforts have been invested in the discovery of protein kinase (PK) inhibitors; however, given that the majority of PKs are still not targeted by an inhibitor with a useful level of selectivity, there is a compelling need to expand the chemical space available for synthesizing new, potent, and selective PK inhibitors. Small-molecule inhibitors targeting the ATP pocket of the catalytic domain of PKs have the potential to become drugs devoid of (major) side effects, particularly if they bind selectively.
View Article and Find Full Text PDFRSC Chem Biol
January 2025
Department of Chemical and Biological Engineering, University of Wisconsin - Madison Madison Wisconsin 53706 USA
Cyanobacteria are widespread, photosynthetic, gram-negative bacteria that generate numerous bioactive secondary metabolites complex biosynthetic enzymatic machinery. The model cyanobacterium sp. strain PCC 7002, hereafter referred to as PCC 7002, contains a type I polyketide synthase (PKS), termed olefin synthase (OlsWT), that synthesizes 1-nonadecene and 1,14-nonadecadiene: α-olefins that are important for growth at low temperatures.
View Article and Find Full Text PDFOrthop J Sports Med
January 2025
Case Western Reserve University School of Medicine, Cleveland, Ohio, USA.
Background: The growing popularity of glucagon-like peptide-1 receptor agonists (GLP-1-RAs) for weight loss could significantly impact joint preservation and arthroplasty. While this will in part be driven by the association between obesity, osteoarthritis (OA), and total joint arthroplasty (TJA), recent evidence also indicates that GLP-1-RAs may have direct joint-protective, anti-inflammatory effects.
Purpose: To evaluate the association between GLP-1-RA use and the onset and progression of hip and knee OA in an obese population.
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