FIG. 3.
HasA secretion through the Has exporters. The plasmids pUC/HasAPF (left), pSYC1000 (middle), and pUC/HasASM (right) encoding the HasA proteins from P. fluorescens, P. aeruginosa, and S. marcescens, respectively, were introduced into the E. coli cells carrying the AprPF (pACYC/AK60), HasPF (pACYC/OI70), and HasSM (pK150) exporters. The polypeptides in the supernatants of the cultured media (1.5 optical density equivalents) were concentrated and then subjected to SDS-PAGE (12.5% acrylamide). The gels were stained with Coomassie brilliant blue G-250. The arrowheads indicate the positions of the HasA proteins, and the positions of molecular mass markers are shown on the left of each gel. Lanes 1, pACYC184; lane 2, pACYC/AK60; lanes 3, pACYC/OI70; lanes 4, pK150.