[Genetic nature of an Escherichia coli mutant characterized by high basal levels of catabolite-sensitive enzymes in a study using glucose as the carbon source].

The genetical nature of Escherichia coli GluR mutant was studied, the mutant having been characterized by an increased basal level of enzymes of the deo-operon (thymidine phosphorylase, in particular,-up to 8-10 times, in comparison to the wild type) and of some other catabolite sensitive enzymes. The above mentioned phenotype turned out to be caused by the presence in the genome of the GluR mutant of the ptsG mutation demonstrating close linkage (98% in P1 transduction) with the crp locus. The latter was designated in this work as crp-active (crpa). It is supposed that the crpa mutation changes the structure of the cAMP receptor--CRP protein increasing its activity, as a positive effector of catabolite sensitive genes.