ANALYSIS OF CIS-ACTING ELEMENTS REQUIRED FOR BFPA EXPRESSION IN ENTEROPATHOGENIC ESCHERICHIA-COLI

bfpA expression in enteropathogenic Escherichia coli is regulated by g rowth medium, temperature, and ammonium concentration and requires the BfpT protein (also called PerA), a member of the AraC family of trans criptional activators, Site-directed and PCR random mutagenesis, as we ll as deletion analysis of the bfpA upstream regulatory region, suppor ted assignment of the promoter elements and demonstrated that the cis- acting elements that mediate BfpT-dependent regulation of bfpA are loc ated between positions -85 and -46, Interestingly, this region shares 73% identity with a 40-bp-long AT-rich tract located upstream of the b fpT gene, which is essential for bfpT autoregulation.