7otc
Cryo-EM structure of an Escherichia coli 70S ribosome in complex with elongation factor G and the antibiotic Argyrin B
Structural highlights
FunctionA0A140N5A3_ECOBD This is 1 of the proteins that binds and probably mediates the attachment of the 5S RNA into the large ribosomal subunit, where it forms part of the central protuberance. In the 70S ribosome it contacts protein S13 of the 30S subunit (bridge B1b), connecting the 2 subunits; this bridge is implicated in subunit movement. Contacts the P site tRNA; the 5S rRNA and some of its associated proteins might help stabilize positioning of ribosome-bound tRNAs.[HAMAP-Rule:MF_01333] Publication Abstract from PubMedArgyrins 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. The cyclic octapeptide antibiotic argyrin B inhibits translation by trapping EF-G on the ribosome during translocation.,Wieland M, Holm M, Rundlet EJ, Morici M, Koller TO, Maviza TP, Pogorevc D, Osterman IA, Muller R, Blanchard SC, Wilson DN Proc Natl Acad Sci U S A. 2022 May 10;119(19):e2114214119. doi: , 10.1073/pnas.2114214119. Epub 2022 May 2. PMID:35500116[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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