Fig. 4.

CsrA^I14M mutant is resistant to inhibition by FliW but still binds FliW in vivo. Western blots of whole-cell lysates grown in the presence of 1 mM IPTG and crosslinked with 0.3% formaldehyde were developed using primary antibodies against CsrA (A) and FliW (B), respectively. Samples in all lanes were prepared from strains containing a deletion of the native csrA gene plus deletion of fliW, as indicated. CsrA proteins of the allele indicated above the line were expressed in trans. The following strains were used to generate lysates for both panels: ΔcsrA P_hyspank-csrA (DK1522), ΔcsrAfliW Physpank-csrA (DK1469), ΔcsrA P_hyspank-csrA^N55D (DK3005), ΔfliWcsrA P_hyspank-csrA^N55D (DK3011), ΔcsrA P_hyspank-csrA^I14M (DK3004), and ΔfliWcsrA P_hyspank-csrA^I14M (DK3010). All panels cropped from two larger gels shown in Fig. S4.