FIGURE 3.
Influence of Crc on the levels of the XylR transcriptional activator. Strain KT2442(pWW0) and its isogenic crc-deficient derivative KT2442C(pWW0) were grown in LB medium in the absence or presence of 3MBA. At mid-exponential phase, cells were collected, and the total proteins were resolved by SDS-PAGE. Proteins were transferred to a polyvinylidene difluoride membrane, and the presence of the XylR protein was probed with a recombinant antibody. The lower panel shows the gel stained with Coomassie Blue, and the upper panel shows the Western blot. Equal amounts of proteins were loaded in all wells of the PAGE gel. Lane C corresponds to a protein extract of P. putida strain KT2442 lacking the pWW0 plasmid. The size of the proteins used as markers is indicated on the left (Mr). wt, wild type.