A role in true-late gene expression for the T4 bacteriophage 5' polynucleotide kinase 3' phosphatase

Two bacteriophage T4-induced, nucleic acid-modifying activities, 5′ polynucleotide kinase and 3′ phosphatase, are both coded by the pse T gene. Therefore, the product of this gene is an enzyme which can remove phosphates from 3′ termini and add them to 5′-hydroxyl termini and thus could be said to “shuttle” phosphates on polynucleotides. This enzyme is sometimes required for T4 true-late gene expression, probably by helping establish the required intracellular DNA structure. Our data suggest that a host gene product normally can substitute for the product of the pse T gene, making it non-essential for phage multiplication on most laboratory strains of Escherichia coli .