title: Heterogeneity of the amino-acid sequences of Escherichia coli Shiga-like toxin type-I operons.
abstract: PCR was used to amplify approx. 1470-bp segments of DNA containing complete Shiga-like toxin type I (sltI) operons from Escherichia coli strains belonging to serotypes O48:H21, O111:H- and OX3:H8. These fragments were cloned and DNA sequence analysis identified several variations, as compared with published sltI sequences. All three sltI genes analysed were more closely related to Shiga toxin-encoding genes (sht) of Shigella dysenteriae type 1, than to previously published E. coli phage-encoded sltI genes. The greatest deviation in deduced amino acid (aa) sequence was observed in the SltI protein from the OX3:H8 strain, which differed from the phage 933J-encoded SltI by 9 aa in the A subunit and 3 aa in the B subunit.
authors.affiliation: Department of Microbiology, Women's and Children's Hospital, North Adelaide, Australia.
authors.forename: A W
authors.initials: AW
authors.lastname: Paton
authors.forename: L
authors.initials: L
authors.lastname: Beutin
authors.forename: J C
authors.initials: JC
authors.lastname: Paton
mesh_terms: D000595:Amino Acid Sequence; D001427:Bacterial Toxins / Q000235:genetics*; D001483:Base Sequence; D004269:DNA, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000145:classification / Q000235:genetics*; D005798:Genes, Bacterial; D014644:Genetic Variation; D008969:Molecular Sequence Data; D009876:Operon; D016133:Polymerase Chain Reaction; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D022622:Shiga Toxin 1
chemical_list: D001427:Bacterial Toxins; D004269:DNA, Bacterial; D022622:Shiga Toxin 1