98%
921
2 minutes
20
A new congener of chuangxinmycin (CM) was identified from CPCC 200056. Its structure was determined as 3-methylchuangxinmycin (MCM) by 1D and 2D NMR. MCM could be generated from CM by heterologous expression of the vitamin B-dependent radical SAM enzyme CxnA/A responsible for methylation of 3-demethylchuangxinmycin (DCM) in CM biosynthesis, indicating that CxnA/A could perform iterative methylation for MCM production. assays revealed significant activities of CM, DCM, and MCM against H37Rv and clinically isolated isoniazid/rifampin-resistant , suggesting that CM and its derivatives may have potential for antituberculosis drug development.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/acs.jnatprod.2c00360 | DOI Listing |
Protein Sci
September 2025
Institute of Bioorganic Chemistry & Bioeconomy Science Center (BioSC), Heinrich Heine University Düsseldorf in Forschungszentrum Jülich, Jülich, Germany.
The pyrroloindole (hexahydropyrrolo[2,3-b]indole, HPI) structural motif is present in a wide range of natural products with various biological activities, yet its chemical synthesis poses a challenge, particularly regarding methylation at the indole C3 position. In nature, S-adenosyl methionine (SAM)-dependent methyltransferases efficiently catalyze this reaction with high stereoselectivity. This study presents the investigation and rational re-design of a potential methyltransferase, termed SeMT, from the actinomycete Saccharopolyspora erythraea.
View Article and Find Full Text PDFiScience
August 2025
School of Medicine, Shenzhen Campus of Sun Yat-sen University, Shenzhen, China.
Detecting tumor-specific DNA methylation in circulating tumor DNA (ctDNA) offers a non-invasive method for tumor detection. The primary challenge lies in identifying the extremely low abundance of ctDNA in cell-free blood plasma (cfDNA). In this study, we present Oncoder, an interpretable deep learning-based tool for economical and accurate non-invasive tumor monitoring and diagnosis.
View Article and Find Full Text PDFLangmuir
August 2025
School of Chemistry and Chemical Engineering, Jiangsu Province Hi-Tech Key Laboratory for Biomedical Research, Southeast University, Nanjing, Jiangsu 211189, P. R. China.
This study aims to enhance the signal-to-noise ratio (SNR) in chemiluminescence immunoassays (CLIA) by increasing the protein immobilization capacity on magnetic bead surfaces. Proteins are macromolecules with three-dimensional conformations where merely increasing the density of surface functional groups on magnetic beads is insufficient to substantially enhance protein immobilization. To address this limitation, we grafted polyamidoamine (PAMAM) dendrimers with three-dimensional architectures onto magnetic beads, simultaneously augmenting the functional group density and expanding the spatial distribution to improve protein loading capacity.
View Article and Find Full Text PDFJ Microbiol Biotechnol
July 2025
College of Medical Technology and Engineering, Henan University of Science and Technology, Luoyang 471023, P.R. China.
Nonribosomal peptides are assembled by large enzymes that contain multiple active sites, which function in a modular manner. The adenylation (A) domains present within typical nonribosomal peptide synthetase (NRPS) modules contain specificity-conferring codes or signature sequences (SNSs). In this study, we obtained 2051 A domain sequences from 67 bacterial species.
View Article and Find Full Text PDFACS Infect Dis
August 2025
Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia 30322, United States.
Among several distinct mechanisms used by bacteria to circumvent antibiotic stress, a predominant form of resistance to ribosome-targeting compounds is the methylation of their ribosomal RNA (rRNA) binding sites. The acquisition of aminoglycoside-resistance methyltransferases that modify 16S rRNA nucleotides in the ribosome decoding center, for example, results in exceptionally high-level aminoglycoside resistance and poses a major threat to their future clinical utility. Here, we report the discovery of a first-in-class panel of small-molecule inhibitors that target a previously unexploited composite "Y-shaped" binding pocket that is unique to the 30S subunit (substrate)-bound form of the 16S rRNA (mA1408) methyltransferase NpmA.
View Article and Find Full Text PDF