Regulatory pattern of the Escherichia coli lysA gene: expression of chromosomal lysA-lacZ fusions

Abstract

The regulation of lysA which encodes the last enzyme for lysine biosynthesis in Escherichia coli, diaminopimelic acid-decarboxylase, was studied by using lysA-lacZ fusions. Our results indicate an absolute requirement for the LysR product for its activation, LysR protein present in a limiting amount which can be titrated by a multicopy plasmid carrying its target site and a negative regulatory role for the LysA protein itself which decreases lysA-lacZ expression 30-fold.