title: The primary structure of the operons coding for Shigella dysenteriae toxin and temperate phage H30 shiga-like toxin.
abstract: Nucleotide(nt) sequences were determined for the toxin (SHT) operon present in the chromosome of Shigella dysenteriae 1 and for the shiga-like toxin (SLT) operon found in the lambdoid phage H30 genome. The coding sequences of the sht and slt genes differ in 4 nt with 1 nt change responsible for an amino acid replacement. The deduced amino acid sequence in the A chain of the toxins is highly homologous to that of the A chain of ricin, a plant toxin. SHT-coding mRNAs were detected by mapping the 5' termini and using blot-hybridisation; one of them was more abundant and coded only for the B subunit of SHT while the other (bi-cistronic mRNA) encoded both subunits. An IS element related to the IS3 element of Escherichia coli was found in the chromosome of S. dysenteriae near the sht operon.
mesh_terms: D000595:Amino Acid Sequence; D001435:Bacteriophages / Q000235:genetics*; D001483:Base Sequence; D003001:Cloning, Molecular; D004274:DNA, Recombinant; D004926:Escherichia coli / Q000235:genetics; D006801:Humans; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D009876:Operon; D012333:RNA, Messenger / Q000235:genetics; D012762:Shigella dysenteriae / Q000235:genetics*; D014118:Toxins, Biological / Q000235:genetics*; D014158:Transcription, Genetic
chemical_list: D004274:DNA, Recombinant; D012333:RNA, Messenger; D014118:Toxins, Biological