Figure 1.

Graphical display of mapped gene fusions near the lac operon. The open arrows indicate the chromosomal genes. The shaded arrows indicate the location and orientation of the chromosomal segments in plasmids from the collection of luxCDABE gene fusions mapped to this region. The direction of the arrowhead indicates whether the DNA of the cloned chromosomal segment is oriented such that a promoter, if present, would be driving expression of genes on the direct (arrowhead to the right) or complementary (arrowhead to the left) strand. In this example, the gene fusions lux-a.pk050.b9, lux-a.pk034.a6, and lux-a.pk065.d4 each contain functional gene fusions of the luxCDABE reporter to the lacZYA promoter.