SRA

Bacterial antibiotic resistance is as a serious health problem. Antibiotic resistance appears either because of mutations or as a result of a bacteria dormant state without heritable genetic change. This non-growing state allows bacteria to survive antibiotic treatment. The mechanisms of entrance to the bacterial dormant state are unknown. It has been suggested that toxin-antitoxin systems (TASs) are possible controlling factors for cell dormancy. In Staphylococcus aureus, the role of TASs genome-wide and their link to the dormancy induction mechanisms has not been investigated in detail. In this study, we analyzed the role of MazF toxin on transcriptome, translatome and proteome of S. aureus using RNA-Seq, Ribo-Seq and quantitative proteomics. We characterized the correlation between transcription, translation, and protein levels, and demonstrated that the MazF endonuclease decreases translation directly by cleaving mRNA, and indirectly, by decreasing translation factors and by promoting ribosome hibernation. Thus, MazF represses transcription and translation of many genes rather than a particular set of genes. Nevertheless, several specific pathways affected by MazF were identified: we demonstrated that cell wall thickness is increased and cell division is decreased upon MazF induction. MazF cleaves mRNA in vivo, creating stop-less transcripts and stalled ribosomes. These stalled ribosomes are rescued by SsrA-system, which is activated upon MazF induction. Finally, we described the overall impact of MazF on S. aureus metabolism, and propose one of the mechanisms by which MazF may induce bacterial dormancy. Overall design: Samples in dupicates RNA-Seq and Ribo-Seq of WT with pRAB11 vector, ?mazEF with pRAB11, and ?mazEF with pRAB11 vector expressing inducible MazF. All samples submited to RNA-Seq and Ribo-Seq.