RNAseq of S. meliloti Rm1021 all ecf/anti-s deletion mutants overexpressing heterologous ecf genes compared to an empty vector control strain

Bacterial s factors are dissociable subunits of the core RNA polymerase and important for promoter recognition and transcription initiation. Extracytoplasmic function (ECF) s factors (ss) represent the most minimalistic and diverse group of alternative ss within the s70 protein family. It has been shown that heterologous ECF ss hold great potential as context independent regulators in a variety of bacterial species and we implemented a core set of 12 heterologous ECF ss and their cognate promoters in Sinorhizobium meliloti. To analyze if heterologous ECF ss affect transcription from the host genome, we overexpressed the ecf02_2817 gene encoding sE from E. coli and the ecf11_0987 gene from Vibrio parahaemolyticus from ~20 copy number plasmid in RFF625c, a S. meliloti Rm1021 strain deleted for all native ECF/anti-s genes (Lang et al. 2018, DOI: 10.1128/mSphereDirect.00454-18) .We compared the RNAseq gene expression profile of these strains to an empty vector control strain.