FIG. 3.

Complementation of the xcpP to -Z deletion in P. aeruginosa strain DZQ40 by the P. alcaligenes xcpP to -Z cluster. Strain DZQ40 contained either pLAFR3, pAX24 carrying the P. aeruginosa xcp gene cluster, or pLAF600 carrying the P. alcaligenes xcp gene cluster. (A) Plate assay demonstrating protease secretion. (B) Immunoblot showing accumulation of elastase inside the cells. Strains were grown on a plate, resuspended in LB medium in order to measure the cell density, pelleted, and resuspended in sample buffer. Equal amounts of cells were loaded and analyzed with an antiserum directed against elastase (arrow). (C) Coomassie brilliant blue-stained gel showing proteins of culture supernatants. The major protein in the pAX24-labeled lane (arrow) is elastase.