Escherichia coli heat-labile enterotoxin: DNA-directed in vitro synthesis and structure.
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منابع مشابه
Escherichia coli heat-labile enterotoxin: DNA-directed in vitro synthesis and structure.
Escherichia coli heat-labile enterotoxin was synthesized in a cell-free system directed by DNA of the plasmid P307. Synthesis of the toxin, assayed by the elongation induced in Chinese hamster ovary cells, was strongly stimulated by cyclic AMP and occurred at physiological levels of Mg2+ only when the polyamine spermidine was present. Activity was abolished by heat and antisera prepared against...
متن کاملHeat - labile Enterotoxin of Escherichia coli
Heat-labile enterotoxin (LT) was obtained in large quantities (several-gram amounts) and great purity from Escherichia coli C600 carrying the LT-coding multicopy plasmid EWD299. By growing this strain on a medium that allows high cell densities in the early stationary phase, we increased the net LT production per milliliter by a factor of 200, compared to natural porcine enterotoxigenic E. coli...
متن کاملEscherichia coli Heat - labile Enterotoxin NUCLEOTIDE SEQUENCE
We report the complete DNA sequence of the Escherichia coli elt A gene, which codes for the A subunit of the heat-labile enterotoxin, LT. The amino acid sequence of the LT A subunit has been deduced from the DNA sequence of elt A. The LT A subunit starts with methionine, ends with leucine, and comprises 264 amino acids. The computed molecular weight of LT A is 29,673. The A subunit of cho...
متن کاملCellular location of heat-labile enterotoxin in Escherichia coli.
We demonstrated that both the A and B subunits of heat-labile enterotoxin from Escherichia coli are located in the periplasm. The toxin was shown to form aggregates in Tris-EDTA buffers which are routinely used for isolating membranes. The aggregates pellet upon centrifugation, and this may explain why several previous investigators have concluded that enterotoxin is associated with membranes.
متن کاملBacteriophage conversion of heat-labile enterotoxin in Escherichia coli.
A temperate phage designated obeta1 (omicron beta) was mitomycin C induced and isolated from heat-labile enterotoxin (LT)-producing Escherichia coli E2631-C2. Phage obeta1 infected the nonlysogenic, nontoxigenic, mitomycin C-sensitive strain of E. coli K-12 (CSH38) and converted it to lysogeny and enterotoxigenicity. After the establishment of lysogeny, E. coli CSH38(obeta1) produced produced L...
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ژورنال
عنوان ژورنال: Proceedings of the National Academy of Sciences
سال: 1979
ISSN: 0027-8424,1091-6490
DOI: 10.1073/pnas.76.10.4832