Bacterial Mutant with Impaired Potassium Transport and Methionine Biosynthesis

A mutant of Escherichia coli has been isolated in which potassium transport and methionine biosynthesis are both impaired. Studies on the nutritional requirements of this organism suggest that the cystathionine cleavage enzyme is impaired. Experiments in low-potassium medium showed that the mutant was unable to maintain the usual high cell potassium concentration. Studies that were made of the mutant and its revertants suggested that a single genetic event was responsible.