Constitutive Expression of Escherichia coli tat Genes Indicates an Important Role for the Twin-Arginine Translocase during Aerobic and Anaerobic Growth

The transcription start sites for the tatABCD and tatE loci, encoding components of the Tat (twin-arginine translocase) protein export pathway, have been identified. Expression studies indicate that the tatABCD and tatE transcription units are expressed constitutively. Translational fusion experiments suggest that TatA is synthesized at a much higher level than the other Tat proteins.