title: The complete nucleotide sequence of the gene encoding the nontoxic component of Clostridium botulinum type E progenitor toxin.
abstract: We have analysed the genes borne on a 6.0 kb HindIII fragment cloned from the chromosome of Clostridium botulinum type E strain Mashike. This fragment, cloned within plasmid pU9EMH, contains part of the structural gene for botulinum toxin type E neurotoxin as well as the entire structural gene for a nontoxic component of botulinum type E progenitor neurotoxin gene, ent-120. ent-120 is transcribed in the same direction as the neurotoxin gene and consists of one open reading frame encoding 1162 amino acid residues. Western blotting with anti-nontoxic component sera demonstrates that ent-120 encodes a protein of 120 kDa which forms part of the nontoxic component. ent-120 is homologous to an analogous gene found in botulinum type C strains (69.3% identity at the nucleotide level and 56.1% at the amino acid level). Two stretches of amino acids at the N-terminus of the ent-120 protein are highly homologous to amino acid sequences within the type E neurotoxin. The stop codon of the ent-120 gene is situated 27 nucleotides upstream from the start codon of the neurotoxin gene.
authors.affiliation: Department of Microbiology, Sapporo Medical College, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Fujii
authors.forename: K
authors.initials: K
authors.lastname: Kimura
authors.forename: N
authors.initials: N
authors.lastname: Yokosawa
authors.forename: T
authors.initials: T
authors.lastname: Yashiki
authors.forename: K
authors.initials: K
authors.lastname: Tsuzuki
authors.forename: K
authors.initials: K
authors.lastname: Oguma
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics; D001427:Bacterial Toxins; D001483:Base Sequence; D015153:Blotting, Western; D001905:Botulinum Toxins / Q000235:genetics*; D003014:Clostridium botulinum / Q000235:genetics*; D004252:DNA Mutational Analysis; D005798:Genes, Bacterial / Q000235:genetics*; D008969:Molecular Sequence Data; D009498:Neurotoxins / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; D001427:Bacterial Toxins; C080139:Clostridium botulinum M toxin; C039811:Clostridium perfringens epsilon-toxin; D009498:Neurotoxins; D001905:Botulinum Toxins