Hybridization probes derived from the A and B subunit genes of the heat-labile enterotoxin (LT) of Escherichia coli were used to analyze DNA from Vibrio cholera strain 569B for cholera toxin gene sequences. Southern blot analysis indicated that the cholera toxin A and B subunit genes were each duplicated in the strain. One of the two toxin subunit gene pairs was cloned as a 5.1-kilobase DNA ins...

The clinical manifestations of cholera are largely attributable to the actions of a secreted hexameric AB5 enterotoxin (choleragen). We have independently solved and refined the three-dimensional structure of choleragen at 2.5 A resolution. The structure of the crystalline toxin closely resembles that described for the heat-labile enterotoxin from Escherichia coli (LT) with which it shares 80% ...

Shigella spp. are food- and waterborne pathogens that cause severe diarrheal and dysenteric disease associated with high morbidity and mortality. Individuals most often affected are children under 5 years of age in the developing world. The existence of multiple Shigella serotypes and the heterogenic distribution of pathogenic strains, as well as emerging antibiotic resistance, require the deve...

Pertussis toxin (PT) has an AB(5) structure that is typical of many bacterial protein toxins; however, this toxin is more complex than many toxins since it is composed of five different subunit types, subunits S1 to S5. Little is known about how PT assembles in vivo and how and when it interacts with its secretion apparatus, known as the Ptl transporter. In order to better understand these even...

The relationship between the structure of the A subunit of pertussis toxin and its function was analyzed. Limited tryptic digestion of the A subunit converted the protein to two stable fragments (M. = 20,000 and 18,000). Antibodies raised to synthetic peptides homologous to regions in the A subunit were used to map these fragments. Both fragments were shown to contain the NHz-terminal portion b...

BACKGROUND AND PURPOSE Non-O1/non-O139 Vibrio cholerae can cause invasive extraintestinal disease as well as enteritis. The pathogenesis of invasive non-O1/non-O139 V. cholerae infections remains to be determined. This study compared the clinical manifestations and predisposing factors between bacteremic and non-bacteremic non-O1/non-O139 V. cholerae infections and examined virulence-associated...

Nucleotide sequences coding for the N- and C-terminus of the A subunit and the N-terminus of the B subunit of cholera toxin were determined. These results show that the genes for the A and B subunits overlap out of phase by one nucleotide and that each subunit is synthesised as a precursor molecule which is subsequently processes after translation. It is proposed that the synthesis of each subu...