FIG. 4.

Schematic representation of the argS-arcA intergenic region. Numbers on the top line refer to the positions relative to the AUG start codon of arcA (0). The indicated fragments were cloned in the pILORI4 promoter expression vector in transcriptional fusion with lacZ. Fragment names are shown on the right. The putative argS transcriptional terminator is indicated by a lollipop, −10 and −35 boxes of the putative promoters P1 and P2 are shown by boxes, and a putative regulatory palindromic structure is shown with arrows. “Reg” denotes regions involved in arginine-dependent regulation (see text for details).