EFFECT OF ULTRAVIOLET IRRADIATION OF BACTERIOPHAGE T2 ON ENZYME SYNTHESIS IN HOST CELLS

Abstract

The kinetics of formation of deoxycytidylate hydroxymethylase, an enzyme induced in Escherichia coli by infection with phage T2, have been studied. Under the usual conditions of infection, enzyme formation takes place during the time interval of 3 to 12 minutes after infection, after which time the enzyme level remains approximately constant. If the cells are infected with phage which has been irradiated with UV light at an appropriate dose, the kinetics of enzyme formation during the first 10 minutes are similar to those observed upon infection with nonirradiated phage. However, enzyme formation continues for a longer period of time after infection with the irradiated phage. This effect has also been noted with 2 other phage-induced enzymes, deoxycyti-dine triphosphatase and thymidylate kinase. Possible implications of this finding are discussed.