8fr3

Publication Abstract from PubMed

trans-Translation is conserved throughout bacteria and is essential in many species. High-throughput screening identified a tetrazole-based trans-translation inhibitor, KKL-55, that has broad-spectrum antibiotic activity. A biotinylated version of KKL-55 pulled down elongation factor thermo-unstable (EF-Tu) from bacterial lysates. Purified EF-Tu bound KKL-55 in vitro with a K (d) = 2 microM, confirming a high-affinity interaction. An X-ray crystal structure showed that KKL-55 binds in domain 3 of EF-Tu, and mutation of residues in the binding pocket abolished KKL-55 binding. RNA-binding assays in vitro showed that KKL-55 inhibits binding between EF-Tu and transfer-messenger RNA (tmRNA) but not between EF-Tu and tRNA. These data demonstrate a new mechanism for the inhibition of EF-Tu function and suggest that this specific inhibition of EF-Tu*tmRNA binding is a viable target for antibiotic development. IMPORTANCE Elongation factor thermo-unstable (EF-Tu) is a universally conserved translation factor that mediates productive interactions between tRNAs and the ribosome. In bacteria, EF-Tu also delivers transfer-messenger RNA (tmRNA)-SmpB to the ribosome during trans-translation. We report the first small molecule, KKL-55, that specifically inhibits EF-Tu activity in trans-translation without affecting its activity in normal translation. KKL-55 has broad-spectrum antibiotic activity, suggesting that compounds targeted to the tmRNA-binding interface of EF-Tu could be developed into new antibiotics to treat drug-resistant infections.

Antibiotic that inhibits trans-translation blocks binding of EF-Tu to tmRNA but not to tRNA.,Marathe N, Nguyen HA, Alumasa JN, Kuzmishin Nagy AB, Vazquez M, Dunham CM, Keiler KC mBio. 2023 Sep 8:e0146123. doi: 10.1128/mbio.01461-23. PMID:37681945^[1]

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