FIG. 2.

Influence of mutated XcpZ proteins on the stability of XcpY in P. aeruginosa. (A) The variant xcpZ genes were subcloned in pMMB67HE and expressed in the xcpZ mutant strain KS902, and the levels of XcpY were analyzed by immunoblotting. Only the relevant portions of the blots are shown. Lane Z, KS902 expressing wild-type xcpZ gene; lane -Z, KS902 bearing pMMB67HE alone. Lane numbers indicate the insertion position in the variant XcpZ. Six independent experiments were performed, and results were found to be reproducible. Protein amounts estimated by scanning densitometry were expressed as percentages of the control value (lane Z), and results are indicated in parentheses. (B) Effect of 175 μM IPTG on the production of variant XcpZ65, -127, -128, and -141. The immunoblot was probed with XcpZ antiserum. (C) Stability of XcpY in the presence of the XcpZ variants used in panel B. The immunoblot was probed with XcpY antiserum.