title: Expression of the B subunit of Escherichia coli heat-labile enterotoxin in a marine Vibrio and in a mutant that is pleiotropically defective in the secretion of extracellular proteins.
abstract: A marine Vibrio (designated Vibrio sp. 60) that is related to Vibrio anguillarum was used as a host for a plasmid that encodes the non-toxic B subunit (EtxB) of Escherichia coli heat-labile enterotoxin. Expression of EtxB in Vibrio sp. 60 resulted in the efficient and selective secretion of the B subunit into the extracellular growth medium. This indicated that Vibrio sp. 60, which does not normally produce cholera-like enterotoxins, nonetheless possesses a secretory machinery that permits these toxins to be translocated across its cytoplasmic and outer membranes. Expression of EtxB in a sec mutant of Vibrio sp. 60 (MVT1192), which had previously been shown to be defective in the secretion of several extracellular proteins, resulted in approximately 95% of the B subunit remaining entrapped within the periplasm of the bacterial cell envelope. This implies that the mutation in MVT1192 defines a locus that determines a common step in the secretion of extracellular proteins, including oligomeric toxins.
authors.affiliation: Department of Genetics, University of Leicester, UK.
authors.forename: R
authors.initials: R
authors.lastname: Leece
authors.forename: T R
authors.initials: TR
authors.lastname: Hirst
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D001427:Bacterial Toxins / Q000096:biosynthesis / Q000235:genetics*; D003470:Culture Media; D004768:Enterotoxins / Q000096:biosynthesis / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins; D015870:Gene Expression; D005822:Genetic Vectors; D009154:Mutation; D010641:Phenotype; D010957:Plasmids; D014733:Vibrio / Q000235:genetics* / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D001427:Bacterial Toxins; D003470:Culture Media; D004768:Enterotoxins; D029968:Escherichia coli Proteins; C027538:heat-labile enterotoxin, E coli