Fig. 7. Amino acid sequence comparison of CdtB from Salmonella typhi, Escherichia coli, and Campylobacter jejuni. Residues that have been shown or are predicted to be essential for the catalytic activity are boxed. The arrowheads indicate the residues of S. typhi CdtB that were mutated in this study. The alignment was constructed with the CLUSTALW program (1).

1. Thompson, J. D., Higgins, D. G. & Gibson, T. J. (1994) Nucleic Acids Res. 22, 4673–4680.