101. Structure and Function of the Bacterial Protein Toxin Phenomycin
- Author
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Kristian M. Jacobsen, Esben B. Svenningsen, Rasmus K. Flygaard, Thomas B. Poulsen, Lasse Jenner, Ditlev E. Brodersen, Thomas Tørring, Jakob Nielsen, Camilla K. Larsen, Bente Krogh Hansen, Lan B. Van, Lene N. Nejsum, Frans A. A. Mulder, Morten Bjerring, univOAK, Archive ouverte, Aarhus University [Aarhus], Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), and Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
natural product ,Protein Conformation ,Endosome ,Bacterial Toxins ,Peptide ,Endosomes ,medicine.disease_cause ,Ribosome ,Cell Line ,Mice ,Structure-Activity Relationship ,03 medical and health sciences ,Eukaryotic translation ,Bacteriocins ,Structural Biology ,[SDV.BBM] Life Sciences [q-bio]/Biochemistry, Molecular Biology ,medicine ,Animals ,Humans ,[SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology ,mini-protein ,Nuclear Magnetic Resonance, Biomolecular ,Molecular Biology ,030304 developmental biology ,Protein Synthesis Inhibitors ,chemistry.chemical_classification ,0303 health sciences ,protein toxin ,Toxin ,Chemistry ,protein synthesis inhibitor ,030302 biochemistry & molecular biology ,Nuclear magnetic resonance spectroscopy ,Amino acid ,Cell biology ,ribosome ,Mutation ,Toxicity ,MCF-7 Cells ,Cell-penetrating peptide ,Intercellular Signaling Peptides and Proteins ,NMR structure ,Eukaryotic Ribosome ,cell-penetrating peptide - Abstract
SummaryPhenomycin is a bacterial mini-protein of 89 amino acids discovered more than 50 years ago with toxicity in the nanomolar regime towards mammalian cells. The protein inhibits the function of the eukaryotic ribosome in cell free systems and appears to target translation initiation. Several fundamental questions concerning the cellular activity of phenomycin have however remained unanswered. In this paper, we have used morphological profiling to show that direct inhibition of translation underlies the toxicity of phenomycin in cells. We have performed studies of the cellular uptake mechanism of phenomycin, showing that endosomal escape is the toxicity-limiting step, and we have solved a solution phase high-resolution structure of the protein using NMR spectroscopy. Through bioinformatic as well as functional comparisons between phenomycin and two homologs, we have identified a peptide segment, which constitutes one of two loops in the structure, that is critical for the toxicity of phenomycin.
- Published
- 2020