FIG. 5.

Proposed operon structure of the Pht cluster of P. syringae pv. phaseolicola. The Pht cluster contains 23 genes arranged into five main transcriptional units, including two monocistronic (argK and phtL) and three polycistronic operons, one comprising 11 genes from phtD to phtK and a second large polycistronic operon comprising 10 genes from phtM to phtV. There is a secondary promoter capable of driving the expression of genes from phtD to phtK. The polycistronic operons are named after the first gene of the operon.