FIG. 1.

Production of inactive MccE492 in hosts carrying mutations in genes involved in the synthesis of enterochelin. (A) Aliquots (3 μl) of liquid cultures of E. coli VCS257 (wt), E. coli H5311 (entC), and E. coli ER1100A (entF) carrying the MccE492 producer system pJEM15 were seeded on a lawn of sensitive cells [E. coli BL21(DE3)], and activity was assessed by the appearance of growth inhibition halos. (B) Sodium dodecyl sulfate-PAGE and immunoblotting of samples of MccE492 purified from the strains mentioned in panel A (lane 1, entC mutant; lane 2, entF mutant; lane 3, wild type).