Identifying novel antibiotics by targeting the EF-Tu complex formation

National Center For Advancing Translational Sciences

Investigators

Abstract

The project team has been able to demonstrate fluorescence resonance energy transfer (FRET) upon assembly of the ternary complex. The modified molecules were capable of carrying out their function in protein biosynthesis normally in vitro. These reagents are thus a powerful tool for rapid HTS screening of small molecule libraries in search for inhibiting ternary complex formation. Although human cells also require ternary complex formation in protein synthesis, eEF-1a, eukaryotic homolog to EF-Tu, is sufficiently different from the bacterial form that it should be possible to find inhibitors of bacterial ternary complex formation that do not affect human ternary complex formation. During this reporting period, the collaborative team tested hits that emerged from EF-Tu high-throughput screening using an assay that detects molecules that can interrupt the interaction between EF-Tu and tRNA. Hit compounds were clustered and prioritized for testing an in orthogonal assays to assess bactericidal activity. Additional analogs of the most promising chemotype were selected for further testing in anti-microbial assays. Molecular modeling was performed using the co-crystal structure of EF-Tu:tRNA to provide insight into potential binding of the hits. The team also worked to develop target engagement assays to demonstrate direct binding of compounds to EF-Tu within bacteria.