Tle1AHis a phospholipase effector secreted by T6SS ofA. hydrophilaNJ-35. A T6SS-dependent secretion of Tle1AH was confirmed by Western blot on whole cells and supernatants of A. hydrophila NJ-35 and the ∆clpV strain. ClpV, which encodes a putative ATPase required for T6SS function, was deleted to construct the T6SS− strain (∆clpV). The anti-His antibody was used to measure the production of Tle1AH and anti-GroEL antibody served as an internal reference. GroEL: heat shock protein Hsp60. B Growth of E. coli TOP10 producing peri-Tle1AH and peri-Tle1AHS303A in LB broth. pBAD/His was used for construction of the expression vectors for tle1AH and its point mutant tle1AHS303A (the catalysis site of Tle1AH at position 303 mutated from serine to alanine). To achieve periplasmic localization, the PelB leader sequence was fused in front of the tle1AH and tle1AHS303A. Cultures were induced by l-arabinose (l-Ara) at the indicated time by the arrow. A growth curve was drawn by measuring the OD600 every 30 min. Data are presented as the mean ± standard deviation (error bars) of three independent experiments. The expression of peri-Tle1AH and peri-Tle1AHS303A was detected in E. coli TOP10 by Western blot using anti-His antibody.