Lowered levels of colicin Ia membrane receptors in an Escherichia coli mutant defective in heme biosynthesis

Cells of an Escherichia coli mutant defective in heme biosynthesis (hemA) grown under conditions for respiration deficiency (grown in the absence of aminolevulinic acid) have 20% of the number of specific colicin Ia receptors found in cells of the same strain grown under conditions for respiration competency (grown in the presence of aminolevulinic acid).