The gene-enzyme relationships of proline biosynthesis in Escherichia coli

Abstract

A simple chromatographic procedure has been devised to separate γ-glutamyl phosphate reductase and 1-pyrroline-5-carboxylate reductase, allowing the measurement of the former in crude E. coli extracts. Analysis of a number of strains of E. coli has demonstrated that gene proA codes for γ-glutamyl phosphate reductase and proB for γ-glutamyl kinase. Introduction of a ColE1 hybrid plasmid containing the proA,B region into a strain with a chromosomal deletion of proA,B led to 3- and 17-fold increases in the specific activities of γ-glutamyl kinase and γ-glutamyl phosphate reductase, respectively.