Amicoumacin A Inhibits Translation by Stabilizing mRNA Interaction with the Ribosome

Abstract

SUMMARY We demonstrate that the antibiotic amicoumacin A (AMI) whose cellular target was unknown, is a potent inhibitor of protein synthesis. Resistance mutations in helix 24 of the 16S rRNA mapped the AMI binding site to the small ribosomal subunit. The crystal structure of bacterial ribosome in complex with AMI solved at 2.4 Å resolution revealed that the antibiotic makes contacts with universally conserved nucleotides of 16S rRNA in the E site and the mRNA backbone. Simultaneous interactions of AMI with 16S rRNA and mRNA and the in vivo experimental evidence suggest that it may inhibit the progression of the ribosome along mRNA. Consistent with this proposal, binding of AMI interferes with translocation in vitro. The inhibitory action of AMI can be partly compensated by mutations in the translation elongation factor G.

Structure of the E. coli ribosome–EF-Tu complex at <3 Å resolution by Cs-corrected cryo-EM

“…1b). The present cryo-EM map visualizes for the first time modifications in rRNA, which were not observable in any of the high-resolution X-ray structures of the bacterial ribosome at 2.4-2.8 Å resolution 5,9 , and were only seen in high-resolution X-ray structures of the Haloarcula marismortui 50S subunit at 2.2-2.4 Å resolution 10 (Extended Data Fig. 4).…”

Purification and characterization of macrolactins and amicoumacins from Bacillus licheniformis BFP011: a new source of food antimicrobial substances

“…The mode of action of amicoumacin A has been associated with inhibition of protein synthesis by suppressing the progression of the ribosome along the mRNA (Polikanov et al, 2014). Taken collectively, these results suggest that the mixture of antimicrobial compounds contained in crude B. licheniformis BFP011 supernatant may prove useful to prevent infections with food-borne pathogens.…”

Overview of 17,856 Compound Screening for Translation Inhibition and DNA Damage in Bacteria

“…This work resulted in identification of the mechanism of action for antibiotic amicoumacin A [17]. Antibacterial activity of this antibiotic was described previously [6], however, its mechanism of action was revealed only in our study [17].…”

“…This reporter construct was previously successfully applied for the screening of soil microorganisms culture broths provided by Gauze Institute of new antibiotics search [12]. This work resulted in identification of the mechanism of action for antibiotic amicoumacin A [17]. Antibacterial activity of this antibiotic was described previously [6], however, its mechanism of action was revealed only in our study [17].…”

“…Automation of the screening process developed in the frame of this project allowed to screen up to 17,856 compound chemical library, supplied by the industrial partner of the project, Research Institute of Chemical Diversity. Among the tested compounds, DNA damaging agents appeared almost sixfold more frequently than those that inhibited protein synthesis.…”