Characterization of a cis-acting regulatory mutation that maps at the distal end of the Escherichia coli glyA gene.

We have isolated a phage Mu cts-generated glyA mutant with only 30% of the normal level of serine hydroxymethyltransferase activity. Genetic and physical mapping studies show that Mu cts has inserted between the end of the glyA structural gene and its proposed transcription termination site. The mutation is cis acting and shows that sequences distal to the glyA structural gene play an important role in the expression of this gene.