Safe and easy evaluation of tmRNA-SmpB-mediated trans-translation in ESKAPE pathogenic bacteria

Bacteria cope with ribosome stalling thanks to trans-translation, a major quality control system of protein synthesis that is mediated by tmRNA, an hybrid RNA with properties of both a tRNA and an mRNA, and the small protein SmpB. Because trans-translation is absent in eukaryotes but necessary for bacterial fitness or survival, it is a promising target for the development of novel antibiotics. To facilitate screening of chemical libraries, various reliable in vitro and in vivo systems have been created for assessing trans-translational activity. However, none of these permits the safe and easy evaluation of trans-translation in pathogenic bacteria, which are obviously the ones we should be targeting. Based on green fluorescent protein (GFP) reassembly during active trans-translation, we have created a cell-free assay adapted to the rapid evaluation of trans-translation in ESKAPE bacteria, with 24 different possible combinations. It can be used for easy high-throughput screening of chemical compounds as well as for exploring the mechanism of trans-translation in these pathogens.