Tetanus toxin: primary structure, expression in E. coli, and homology with botulinum toxins.

Abstract

A pool of synthetic oligonucleotides was used to identify the gene encoding tetanus toxin on a 75‐kbp plasmid from a toxigenic non‐sporulating strain of Clostridium tetani. The nucleotide sequence contained a single open reading frame coding for 1315 amino acids corresponding to a polypeptide with a mol. wt of 150,700. In the mature toxin molecule, proline (2) and serine (458) formed the N termini of the 52,288 mol. wt light chain and the 98,300 mol. wt heavy chain, respectively. Cysteine (467) was involved in the disulfide linkage between the two subchains. The amino acid sequences of the tetanus toxin revealed striking homologies with the partial amino acid sequences of botulinum toxins A, B, and E, indicating that the neurotoxins from C. tetani and C. botulinum are derived from a common ancestral gene. Overlapping peptides together covering the entire tetanus toxin molecule were synthesized in Escherichia coli and identified by monoclonal antibodies. The promoter of the toxin gene was localized in a region extending 322 bp upstream from the ATG codon and was shown to be functional in E. coli.

The N‐terminal half of the heavy chain of botulinum type A neurotoxin forms channels in planar phospholipid bilayers

“…The genes for both tetanus toxin [17] and diphtheria toxin [18,19] have been cloned and sequenced and the primary structures of these toxin proteins thereby deduced. In recent years, the use of molecular cloning techniques in the study of ionic channels has provided a unique probe into the molecular mechanisms which underlie channelforming activity.…”

Reductive chain separation of botulinum A toxin — a prerequisite to its inhibitory action on exocytosis in chromaffin cells

“…A similar molecular mechanism for the action of Tetx and Botx A within the cells has been predicted from their primary structure [23]. However, from studies using mouse hemidiaphragm, different effects of Tetx and Botx A have been deduced [24].…”

The genome sequence of Clostridium tetani , the causative agent of tetanus disease

“…So far, genetic information on C. tetani is mainly restricted to the nucleotide sequences of the tetanus toxin TeTx and of its direct transcriptional activator TetR, both of which are encoded on a plasmid, designated pCL1 in the strain Massachusetts (7)(8)(9)(10). The identification and analysis of all genes in the genome of C. tetani will contribute to our understanding of the lifestyle switch from a harmless soil bacterium to a potentially devastating neurosystem-damaging organism after entering and infecting a mammalian host.…”