FIG. 1.

Construction of the plasmid csrA::kan (a) for the inactivation of csrA_Bb and of CsrA/pBBE22G (b) for the complementation of the csrA_Bb mutant. (a) To construct the csrA::kan plasmid, the flanking regions of bb0184 (csrA_Bb) were amplified by PCR and ligated. The whole bb0184 gene was omitted and replaced with kan in the final construct. (b) P_flgK, the flgK promoter upstream of bb0180 (17), was amplified by PCR and fused to the 5′ end of bb0184. The obtained fragment was further cloned into the shuttle vector pBBE22G (54).