Control by bacteriophage T4 of the reduction of adenosine nucleotide to deoxyadenosine nucleotide.

After infection with bacteriophage T4, Escherichia coli B shows an increase in activity for reduction of adenosine diphosphate to deoxyadenosine diphosphate. An allosteric effector appears to be deoxyguanosine triphosphate, which is needed to reveal the activity in crude extracts of the infected cells. The enzyme system determined by the three phage genes, nrdA, B, and C, is involved in the reduction of all of the ribonucleoside diphosphates, ADP, GDP, UDP, and CDP. A sensitive assay for ribonucleotide reductase was developed which was based on the separation of the reaction products by polyethyleneimine cellulose thin layer chromatography.