| 摘要 |
The complete nucleotide sequence of the pertussis toxin gene and the deduced amino acid sequences of the individual subunits have been determined. All five subunits are coded by closely linked cistrons and possibly expressed through a polycistronic mRNA, since a promotor-like structure was found in the 5' flanking region. The order of the cistrons is S1, S2, S3, S4, S5, and S3. All subunits contain signal peptides of variable length. The calculated molecular weights of the mature subunits are 25,024 for S1, 21,924 for S2, 21,873 for S3, 12,058 for S4 and 11,013 for S5. All subunits contain signal peptides of variable length. Subunits S2 and S3 share 70% amino acid homology and 75% nucleotide homology. Subunit S1 contains two regions of eight amino acids homologous to analogous regions in the A subunit of both cholera and E. coli heat labile toxins. Functional domains in relation to the primary structure and the development of a safer, new generation vaccine against whooping cough are presented.
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