Pseudomonas aeruginosa LasD processes the inactive LasA precursor to the active protease form

LasA and LasD are staphylolytic proteinases which are secreted by the opportunistic pathogen Pseudomonas aeruginosa. We have previously described the purification and characterization of both LasA and LasD, a 21-kDa protein which shares many of the enzymatic properties of LasA. In this follow-up study we describe the isolation of the 42-kDa precursor of LasA (proLasA) and demonstrate the ability of the purified LasD proteinase to cleave the inactive proLasA to the 20-kDa active form of the proteinase.