Fig. 1.

EUO binds and represses the C. trachomatis omcAB promoter.

A. EMSA experiments with upstream (nucleotides –122 to –60 relative to the start of transcription) or downstream regions (–58 to +5) of the omcAB promoter. The upstream probe was incubated with 0, 80, 160, 320 or 640 nM rEUO, while the downstream probe was incubated with 0, 80, 160 or 320 nM rEUO. Bands corresponding to the bound and free probes are indicated on the right.

B. Western blot verifying that the bound probe contains EUO. EMSA reaction for the downstream omcAB probe was performed in the absence or presence of 10 μM His-tagged rEUO and then transferred to nitrocellulose membrane and hybridized with anti-His antibodies. Bands corresponding to the bound DNA fragment are indicated to the right.

C. In vitro transcription of the omcAB promoter (pMT1150) by E. coli RNA polymerase or C. trachomatis RNA polymerase, as indicated, in the absence or presence of 2.5 μM EUO.