FIG. 1.

Proteomic analysis of the effect of Crc in P. putida cells growing exponentially in LB medium. Total proteins obtained from strains PBS4 (wild type for crc) and PBS4C1 (contains an inactivated crc allele), exponentially growing in LB medium, were resolved by 2-D electrophoresis. Proteins were first separated according to their isoelectric point by IEF and then resolved through a 12.5% (wt/vol) denaturing polyacrylamide gel. Protein spots were revealed by silver staining. The figure shows areas of the 2-D gels containing spots whose intensity reproducibly decreased or increased by inactivation of crc in at least three independent assays. These proteins were excised from the gel and identified by mass spectrometry; the results are indicated in Table 1. Panels on the left correspond to strain PBS4 (crc⁺) while those on the right correspond to strain PBS4C1 (crc::tet).