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Publication Abstract from PubMed

Ribosome-targeting antibiotics serve as powerful antimicrobials and as tools for studying the ribosome, the catalytic peptidyl transferase center (PTC) of which is targeted by many drugs. The classic PTC-acting antibiotic chloramphenicol (CHL) and the newest clinically significant linezolid (LZD) were considered indiscriminate inhibitors of protein synthesis that cause ribosome stalling at every codon of every gene being translated. However, recent discoveries have shown that CHL and LZD preferentially arrest translation when the ribosome needs to polymerize particular amino acid sequences. The molecular mechanisms that underlie the context-specific action of ribosome inhibitors are unknown. Here we present high-resolution structures of ribosomal complexes, with or without CHL, carrying specific nascent peptides that support or negate the drug action. Our data suggest that the penultimate residue of the nascent peptide directly modulates antibiotic affinity to the ribosome by either establishing specific interactions with the drug or by obstructing its proper placement in the binding site.

Structural basis for the context-specific action of the classic peptidyl transferase inhibitor chloramphenicol.,Syroegin EA, Flemmich L, Klepacki D, Vazquez-Laslop N, Micura R, Polikanov YS Nat Struct Mol Biol. 2022 Feb;29(2):152-161. doi: 10.1038/s41594-022-00720-y. , Epub 2022 Feb 14. PMID:35165455^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.