FIG. 1.

Transcriptional fusions used in this study. λ354 contains the pap regulatory region, λ366 contains the daa regulatory region, and λMW01 contains the fan regulatory region (Table 1). Each transcriptional fusion is carried on the E. coli chromosome as a lambda lysogen. Open boxes indicate fimbrial genes and lacZYA sequences contained within each fusion. Transcription of lacZYA is driven by the pBA promoter of the pap operon, the pA promoter of the daa operon, and the pA promoter of the fan operon.