Unlocking Cryptic Metabolites with Mass Spectrometry-Guided Transposon Mutant Selection. Author Aya Yoshimura, Brett Covington, Étienne Gallant, Chen Zhang, Anran Li, Mohammad Seyedsayamdost Publication Year 2020 Type Journal Article Abstract The products of most secondary metabolite biosynthetic gene clusters (BGCs) have yet to be discovered, in part due to low expression levels in laboratory cultures. Reporter-guided mutant selection (RGMS) has recently been developed for this purpose: a mutant library is generated and screened, using genetic reporters to a chosen BGC, to select transcriptionally active mutants that then enable the characterization of the "cryptic" metabolite. The requirement for genetic reporters limits the approach to a single pathway within genetically tractable microorganisms. Herein, we utilize untargeted metabolomics in conjunction with transposon mutagenesis to provide a global read-out of secondary metabolism across large numbers of mutants. We employ self-organizing map analytics and imaging mass spectrometry to identify and characterize seven cryptic metabolites from mutant libraries of two different species. Applications of the methodologies reported can expand our understanding of the products and regulation of cryptic BGCs across phylogenetically diverse bacteria. Keywords Mutagenesis, Mass Spectrometry, Multigene Family, Metabolomics, Biological Products, Burkholderia, DNA Transposable Elements, Metabolome, Secondary Metabolism Journal ACS Chem Biol Volume 15 Issue 10 Pages 2766-2774 Date Published 2020 Oct 16 ISSN Number 1554-8937 DOI 10.1021/acschembio.0c00558 Alternate Journal ACS Chem Biol PMCID PMC7572862 PMID 32808751 PubMedPubMed CentralGoogle ScholarBibTeXEndNote X3 XML