ORGANIZATION AND NUCLEOTIDE-SEQUENCE OF GENES FOR HEMAGGLUTININ COMPONENTS OF CLOSTRIDIUM-BOTULINUM TYPE-B PROGENITOR TOXIN

The genes for hemagglutinin components (33 kD, 17 kD, and 21.5 kD) of Clostridium botulinum type B progenitor toxin were cloned and sequence d. Analysis of the nucleotide sequence showed that the 33 kD, 17 kD, a nd 21.5 kD hemagglutinin genes were organized into an operon in the 5' upstream region of the toxin gene and their ORF orientation were oppo site to that of the toxin gene. A comparison of amino acid sequences b etween the hemagglutinin components in type B and type C progenitor to xin showed significant homology. Northern blot analysis also revealed that all of the genes for the hemagglutinin components were transcribe d as a polycistronic RNA.