Argyrins are a family of naturally produced octapeptides that display promising antimicrobial activity against Pseudomonas aeruginosa. Argyrin B (ArgB) has been shown to interact with an elongated form of the translation elongation factor G (EF-G), leading to the suggestion that argyrins inhibit protein synthesis by interfering with EF-G binding to the ribosome. Here, using a combination of cryo-electron microscopy (cryo-EM) and single-molecule fluorescence resonance energy transfer (smFRET), we demonstrate that rather than interfering with ribosome binding, ArgB rapidly and specifically binds EF-G on the ribosome to inhibit intermediate steps of the translocation mechanism. Our data support that ArgB inhibits conformational changes within EF-G after GTP hydrolysis required for translocation and factor dissociation, analogous to the mechanism of fusidic acid, a chemically distinct antibiotic that binds a different region of EF-G. These findings shed light on the mechanism of action of the argyrin-class antibiotics on protein synthesis as well as the nature and importance of rate-limiting, intramolecular conformational events within the EF-G-bound ribosome during late-steps of translocation.
Organizational Affiliation:
Institute for Biochemistry and Molecular Biology, University of Hamburg, 20146 Hamburg, Germany.
St. Jude Children's Research Hospital, Memphis, TN 38105.
Weill Cornell Medicine, Tri-Institutional PhD Program in Chemical Biology, New York, NY 10065.
Center of Life Sciences, Skolkovo Institute of Science and Technology, 121205 Moscow, Russia.
Department Microbial Natural Products, Helmholtz Institute for Pharmaceutical Research Saarland, Helmholtz Centre for Infection Research, Saarland University, 66123 Saarbrücken,Germany.
Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia.
IB [auth 16] JB [auth 16] JE [auth 23] KE [auth 23] LE [auth 23]
IB [auth 16], JB [auth 16], JE [auth 23], KE [auth 23], LE [auth 23], ME [auth 23], NE [auth 23], OE [auth 23], PE [auth 23], QE [auth 23], RE [auth 23]
Download Mendeley
