Fig. 2.
Evidence that secretins decrease the membrane potential in an E. coli psp null strain but non-secretin Psp-inducers do not. E. coli psp+ (MC3) and Δ(pspF-pspE) (AJDE2419) strains contained pVLT35-based vectors encoding Y. enterocolitica Psp-inducers. For all panels IPTG was added to cultures at 200 μM for empty pVLT35 vector (−) and YscC, none for YsaC, 25 μM for AmpE, and 5 μM for YE0566.
A. Φ(pspA-lacZ) operon fusion expression in the psp+ strain. Cultures were grown as described in Experimental procedures. Error bars represent one positive standard deviation.
B. Growth of the psp+ and Δ(pspF-pspE) stains. Optical density was determined hourly. C. [3H]-TPP+ accumulation by whole cells grown as in panel A. Error bars represent one positive standard deviation. CPM = counts per minute.
