Bacteriophage PBS2-induced deoxycytidine triphosphate deaminase in Bacillus subtilis

The dCTP deaminase induced by Bacillus subtilis bacteriophage PBS2, whose DNA contains uracil instead of thymine, requires metal ion and thiol activators and has a molecular weight of 125,000. The enzyme displays sigmoidal substrate saturation kinetics and inhibition by dUTP, consistent with the deaminase's proposed role of providing balanced levels of dUTP and dCTP for PBS2 uracil-DNA synthesis.