Transcriptomic study of E. coli 042 with a variant of aggR gene with a FRT sequence inserted in its 3´UTR by RNA-seq

A common genomic feature of most EAEC strains is the presence of a virulence plasmid termed pAA. Plasmid-encoded virulence determinants are, among others, a transcriptional activator termed AggR, a member of the AraC-XylS family of transcription factors. We have previously determined the direct correlation between (p)ppGpp, expression of AggR and biofilm development in strain EAEC 042 (https://doi.org/10.3389/fmicb.2018.00717). In this work we characterize a novel variant of the aggR gene. We modified its 3´UTR by insertion of a FRT sequence, which have generated a series of different phenotypes. We used RNA-seq to compare the transcriptome of the wt strain and its aggR3UTRFRT variant grown at 37ºC in LB medium. Overall design: E. coli 042 and derivative aggR3UTRFRT mRNA profiles were generated by Illumina RNA-seq. RNA extraction, DNase treatment, evaluation of RNA quality and cDNA libraries for Illumina sequencing were performed by Vertis Biotechnologie AG, Freising-Weihenstephan, Germany. Bacterial cells were grown until O.D.600 of 2.0 in LB medium at 37ºC with 200rpm of agitation. Three replicates were grown from each strain, 1 ml of each replicate was collected and bacterial pellets were maintained at -80ºC. Bacterial pellets were sent to Vertis Biotechnologie AG, Freising-Weihenstephan, Germany in dry ice. E. coli 042 wt was used as genome reference (NC_017626 for the chromosome and NC_017627 for the pAA plasmid) for analysis.