%0 Journal Article
%T Comparative Genomics and Characterization of the Late Promoter pRĄŻ from Shiga Toxin Prophages in Escherichia coli
%A David J. Simpson
%A Ling Xiao Zhang
%A Lynn M. McMullen
%A Michael G. GŁżnzle
%J Archive of "Viruses".
%D 2018
%R 10.3390/v10110595
%X Shiga-toxin producing Escherichia coli (STEC) causes human illness ranging from mild diarrhea to death. The bacteriophage encoded stx genes are located in the late transcription region, downstream of the antiterminator Q. The transcription of the stx genes is directly under the control of the late promoter pRĄŻ, thus the sequence diversity of the region between Q and stx, here termed the pRĄŻ region, may affect Stx toxin production. Here, we compared the gene structure of the pRĄŻ region and the stx subtypes of nineteen STECs. The sequence alignment and phylogenetic analysis suggested that the pRĄŻ region tends to be more heterogeneous than the promoter itself, even if the prophages harbor the same stx subtype. Furthermore, we established and validated transcriptional fusions of the pRĄŻ region to the DsRed reporter gene using mitomycin C (MMC) induction. Finally, these constructs were transformed into native and non-native strains and examined with flow cytometry. The results showed that induction levels changed when pRĄŻ regions were placed under different regulatory systems. Moreover, not every stx gene could be induced in its native host bacteria. In addition to the functional genes, the diversity of the pRĄŻ region plays an important role in determining the level of toxin induction
%K Shiga toxin prophage
%K genomic characterization
%K flow cytometry
%K microscope
%K phage induction efficiency
%K sequence diversity
%U https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6266700/