FIG. 4.

Schematic representation of plasmids carrying the EPEC tir region. The name of the plasmid is shown at left next to a schematic representation of the LEE region cloned into pBluescript (pSK). orf19 encodes a protein which is translocated into host cells, where it appears to interfere with mitochondrial function (26), while orfU (renamed cesT) encodes a Tir chaperone molecule (1, 11). tirHSV is a 3′ in-frame fusion of tir with the sequence encoding an HSV epitope. This tag does not interfere with Tir delivery or modification or actin-nucleating function following transfer into host cells by EPEC (21). eae encodes the intimin protein, with only a small portion of it present in these constructs. Restriction enzyme sites used in the generation of these constructs are also shown.