Analysis of delta-crcZ suppressor mutations
The delta crcZ mutant shows constitutive repression of all Crc Hfq target genes in the translation. Therefore, it presents a hyperrepressed phenotype (more repressed than the parental strain) in the acquisition of secondary carbon sources, even though the preferred carbon source is not present. When the delta crcZ mutant is seeded on minimal medium with a secondary carbon source it grows poorly. However, the appearance of colonies that grow similarly to the parental strain is observed. These colonies are formed from mutants derived from the delta crcZ strain that are revertants of this repression phenotype in the assimilation of the secondary carbon source, and generally pseudorevertants of the delta crcZ mutation, or present a mutation suppressor of the CrcZ deletion. 4 mutant clones resistant to FAA (FAA resistant, present catabolic repression) and sensitive clones (FAA sensible, do not present catabolic repression) were analyzed. In the FAA sensible category are the strains delta crcZr and the strain delta crc. These clones are, in general, more sensitive to antibiotics and oxidative stress and less motile. In the FAA resistant category are delta crcZe clones that have similar phenotypes to strain delta crcZ and strain PAO1 and are generally more resistant to antibiotics and oxidative stress, more motile and more virulent. An RNAseq experiment was performed on the previously chosen pseudorevertant mutants to use this information as a fingerprint of the action of the Crc mutant variants in the delta crcZ gene context