Introduction of the rol genes of Shigella dysenteriae 1 and Escherichia coli K-12 into Shigella flexneri carrier strains expressing the heterologous S. dysenteriae type 1 lipopolysaccharide resulted in the formation of longer chains of S. dysenteriae 1 O antigen. In bacteria producing both homologous and heterologous O antigen, this resulted in a reduction of the masking of heterologous O antigen by homologous lipopolysaccharide and an increased immune response induced by intraperitoneal immunization of mice by recombinant bacteria. The rol genes of S. dysenteriae 1 and E. coli K-12 were sequenced, and their gene products were compared with the S. flexneri Rol protein. The primary sequence of S. flexneri Rol differs from both E. coli K-12 and S. dysenteriae 1 Rol proteins only at positions 267 and 270, which suggests that this region may be responsible for the difference in biological activities.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC178982 | PMC |
http://dx.doi.org/10.1128/jb.179.7.2421-2425.1997 | DOI Listing |
NPJ Antimicrob Resist
April 2024
Institute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK.
Antimicrobial resistance can arise in the natural environment via prolonged exposure to the effluent released by manufacturing facilities. In addition to antibiotics, pharmaceutical plants also produce non-antibiotic pharmaceuticals, both the active ingredients and other components of the formulations. The effect of these on the surrounding microbial communities is less clear.
View Article and Find Full Text PDFUnlabelled: The activity of DNA adenine methyltransferase (Dam) and DNA cytosine methyltransferase (Dcm) together account for nearly all methylated nucleotides in the K-12 MG1655 genome. Previous studies have shown that perturbation of DNA methylation alters global gene expression, but it is unclear whether the methylation state of Dam or Dcm target sites regulates local transcription. In recent genome-wide experiments, we observed an underrepresentation of Dam sites in transcriptionally silent extended protein occupancy domains (EPODs), prompting us to hypothesize that EPOD formation is caused partially by low Dam site density.
View Article and Find Full Text PDFACS Infect Dis
January 2025
Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts 02115, United States.
Carbapenemase producing (CPEs) represent a group of multidrug resistant pathogens for which few, if any, therapeutics options remain available. CPEs generally harbor plasmids that encode resistance to last resort carbapenems and many other antibiotics. We previously performed a high throughput screen to identify compounds that can disrupt the maintenance and replication of resistance conferring plasmids through use of a synthetic screening plasmid introduced into K-12 cells.
View Article and Find Full Text PDFMicrobiol Resour Announc
December 2024
Research Department for Limnology, Mondsee, Universität Innsbruck, Mondsee, Austria.
mSystems
January 2025
Department of Bioengineering, University of California, San Diego, California, USA.
Unlabelled: The composition of bacterial transcriptomes is determined by the transcriptional regulatory network (TRN). The TRN regulates the transition from one physiological state to another. Here, we use independent component analysis to monitor the composition of the transcriptome during the transition from the exponential growth phase to the stationary phase.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!