Fructose bisphosphatase of Escherichia coli: cloning of the structural gene (fbp) and preparation of a chromosomal deletion

The fbp locus at 96 min on the Escherichia coli chromosome governs fructose bisphosphatase (fructose-1,6-P2 1-phosphatase). We have cloned and subcloned fbp on vector pBR322 to obtain strains with high levels of the enzyme. In vivo mutagenesis of the clone was used to show that fbp is the structural gene. The gene was deleted on the plasmid in vitro, and the chromosomal wild-type locus was replaced with this deletion by a method involving stabilization of a heterozygous intermediate resulting from plasmid integration, followed by segregation of the wild-type gene.