FIG 1.
mgtE inhibits T3SS gene expression at the posttranscriptional level. (A) PA103 PexsD-lacZ (WT) and UY241 were assayed under either T3SS-noninducing (–EGTA) or -inducing (+EGTA) conditions and assayed for β-galactosidase activity from the PexsD-lacZ reporter construct. The percentage of activity was calculated considering the PexsD-lacZ activity in EGTA-treated WT as 100%. *, P < 0.0005; n.s., not significant. (B) PA103 PexsD-lacZ (WT) with either the vector control or pmgtE was assayed under T3SS-inducing conditions, and β-galactosidase activity from the PexsD-lacZ construct was measured. The percentage of activity was calculated considering the PexsD-lacZ activity in the WT with blank vector as 100%. **, P < 0.05. (C) Strain UY241 with either the vector control or pmgtE was assayed under T3SS-inducing conditions, and β-galactosidase activity from the PexsD-lacZ construct was measured. The percentage of activity was calculated considering the PexsD-lacZ activity in UY241 with blank vector as 100%. ***, P < 0.005.