Physical Characterization of Clostridium Botulinum Neurotoxin Genes
Final rept. 2 Jul 1990-1 Sep 1993
PUBLIC HEALTH LAB SERVICE PORTON DOWN (UNITED KINGDOM)
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A total of 4 structural genes bot encoding botulinum neurotoxins BoNT have been cloned and their entire nucleotide sequences determined. These are the genes of the proteolytic Clostridium botulinum strains Danish type B, NCTC 11219 type E Langeland type F, and 89G type G. The encoded toxins comprise 1291, 1252, 1278 and 1297 amino acids aa, respectively. The determined BoNTF sequence exhibits considerable divergence from that of a BoNT F derived from a non-proteolytic strain of C botulinum ATCC 23387, and the BoNTF produced by a strain of Clostridium baratii ATCC 43756. Similar levels of divergence appear to exist between proteolytic and non-proteolytic type B neurotoxins. One consequence is that a vaccine based on the H sub c polypeptide of a single representative of a particular serotype notably types B and F may not give protection against all members of that serotype. Attempts to impose control on a Clacetobutylicum expression system were unsuccessful. Gene fusions were constructed between a glutathione-S-transferase gene and botA DNA encoding various portions of the BoNTA H-chain. No direct evidence for the production of recombinant protein in C acetobutylicum was obtained. Foreign, BD, Clostridium, Cloning, Vaccines, BL3, Biotechnology, Gene expression, Gene cloning, DNA transfer, Neurotoxin genes, Clostridium botulinum.