Cyclic Adenosine Monophosphate Receptor Protein (CRP) is Required for the Expression of CS3 and CFA/I pili of Enterotoxigenic Escherichia coli

2020-05-30T15:04:36Z (GMT) by George Munson
CRP and cAMP are required for the expression of CS3 and CFA/I pili.
Western blots from three independent cultures of wild–type ETEC strains (1392-75-2a and H10407) and their crp::kan and cyaA::kan derivatives cultured aerobically at 37°C in CFA medium. For complementation crp mutants were transformed with pHG165 (vector) or pSE186 (crp+). Alternatively the indicated cultures of cyaA mutants were supplemented with 3mM cAMP. For each blot lanes were loaded with equivalent amounts of total soluble, heat extracted proteins. Accordingly, lanes were loaded with A) 300, B) 476, C) 300, or D) 260 ng of protein. As indicated blot were probed with polyclonal antibodies raised against CS3 or CFA/I pili. The CS3 and CFA/I major pilins (accession numbers AAA23614 and E3PPC4 respectively) have expected molecular masses of 15 kDa after signal peptide cleavage.