Fig. 5.

Determination of the ArgP-binding site within the lysP control region. DNase I digestion patterns were determined for a DNA fragment from position −218 to position +58 of the lysP control region labeled with fluorescein at the 5′ end of the top strand. Panel A shows the restriction pattern obtained in the absence of purified ArgP-His₆, and panels B and C show the pattern obtained in the presence of 4.3 μM purified protein in the absence (B) or presence (C) of 0.1 mM lysine. Regions protected by ArgP (position −91 to −77 and −70 to −47) are encircled.