FIG. 4.
Effects of the suppressor mutation and divalent cations on the functionality and production of various XcpQ proteins. P. aeruginosa strains PAN1 and PAN16 containing the empty vector (−) or xcpQaer, xcpQF497, xcpQF459, xcpQF87, or xcpQalc on plasmids were grown in normal LB medium or LB medium supplemented with 5 mM MgCl2 (Mg). Extracellular proteins were precipitated with 5% TCA and separated by SDS-PAGE (A). The position of the major protein secreted via the type II pathway, elastase, is indicated by an arrow. (B) Amounts of XcpQ oligomers produced by the strains. Cell envelopes were subjected to SDS-PAGE followed by Western blotting with polyclonal antibodies directed against XcpQ. The position of the XcpQ oligomers is indicated by an arrow.