dUTPase

dUTPase is an enzyme of deoxyribonucleotide metabolism that converts dUTP to dUMP, as follows:

> dUTP + H 2O <=> dUMP + PPi

This reaction is part of the de novo biosynthetic pathway leading to dTTP (Figure 22.17). In addition, the enzyme has the important effect of lowering the concentration of dUTP in the cell. dUTP can be incorporated by DNA polymerase into DNA in place of dTTP. This can be problematic, because deamination of the uracil base converts it to cytosine. If this happens in DNA, a mutation will result.

See also: Ribonucleotide Reductase and Deoxyribonucleotide Biosynthesis, Biosynthesis of Thymine Deoxyribonucleotides, Deoxyuridine Nucleotide Metabolism

INTERNET LINK: Pyrimidine Metabolism