FIG. 1.

Clustal alignment of full-length Tir proteins, showing that C. rodentium Tir is most similar to that of the human EPEC strain E2348/69. When carboxyl-terminal intimin peptides are similarly analyzed, C. rodentium clusters with the rabbit EPEC strain RDEC-1, demonstrating the difficulty in identifying a precursor organism for the C. rodentium LEE. The tree was arbitrarily anchored with the C. rodentium EspB protein, as Tir does not show appreciable homology to any protein previously reported. GenBank accession numbers are AF125993 (EHEC EDL933), AF022236 (EPEC E2348/69), AF045568 (RDEC-1), AJ223063 (EHEC 413/89-1), and AF177537 (C. rodentium EspB).