Similarly to Escherichia coli K-12 IAM 1264, trans-4- guanidinomethylcyclohexanecarboxylic acid 4-tert-butylphenyl ester (GMCHA-OPhtBu), a trypsin inhibitor, had a strong inhibitory effect on the growth of various strains of E. coli K-12, such as W 3350, AB 1157, JM 103, W 3110, C 600r-m- and C 600r+m+, preceded by suppressive effects of GMCHA-OPhtBu on DNA synthesis in these strains, although the inhibitory effects varied from strain to strain. These results suggested the possible involvement of a trypsin-like proteinase in DNA synthesis. A trypsin-like proteinase was partially purified from E. coli K-12 AB 1157 by ammonium fractionation and successive chromatographies on DEAE-cellulose, Sephadex G-100 and arginine-Sepharose 4B columns. The properties were compared with those of proteinase In, which instantly appears just before the onset of DNA synthesis and seems to participate in the initiation of DNA replication, and which was purified from E. coli K-12 IAM 1264. The proteinase from E. coli K-12 AB 1157 was identified with proteinase In. These results suggest that proteinase In must be widely distributed in various E. coli strains and plays a pivotal role in the onset of DNA replication.
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http://dx.doi.org/10.1248/bpb.16.621 | 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.
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