Fig. 4: Plasmid-chromosome transcriptional crosstalk.

A Schematic representation of the plasmid-chromosome crosstalk mediated by the pOXA-48-encoded LysR transcriptional regulator. In the presence of pOXA-48, the overexpression of the operon genes is mediated by LysR_pOXA-48 (solid red arrow). The thick red arrow represents the putative promoter of the operon. Chromosome and plasmid are represented at different scales, indicated in the figure. B Zoom in on the pOXA-48ΔlysR plasmid. The lysR gene of pOXA-48 was knocked-out by inserting the aph(3’)-IIa resistance gene. C Map of the pTet-LysR plasmid. The expression of lysR_pOXA-48 is controlled by the inducible promoter P_tet. D RT-qPCR results for the expression of lysR_pOXA-48, bla_OXA-48 and the pfp-ifp operon (pfp levels as proxy for the entire operon). Levels of expression are normalized to the endogenous control rpoB and represented as the log₂FC of gene expression compared to rpoB. Error bars represent the standard error of the mean (n = 2 biological replicates, each as the median of 3 technical replicates). Source data are provided as a Source Data file.