β-Galactosidase: Inactivation of Its Messenger RNA by Ultraviolet Irradiation

A brief exposure of Escherichia coli cells to an inducer for β -galactosidase results in the production of a messenger RNA which subsequently expresses itself as β-galactosidase. Ultraviolet irradiation of cells after exposure to the inducer results in a decrease in the amount of β-galactosidase formed. The messenger RNA formed during the brief exposure to inducer is evidently inactivated by the ultraviolet radiation. The decay of messenger RNA activity in irradiated cells has the same kinetics as that observed in unirradiated cells.