dUTP

Deoxyuridine triphosphate (dUTP) is a deoxyribonucleoside triphosphate that can serve as a substrate for DNA polymerases during DNA synthesis. As a close analogue of dTTP, it can be incorporated into DNA in place of thymidine, introducing uracil into the DNA strand if not removed.

In cells, dUTP is kept at very low concentrations relative to dTTP by the action of dUTPase, an enzyme that hydrolyzes dUTP to dUMP and pyrophosphate. This rapid hydrolysis minimizes uracil incorporation and maintains genomic stability. When dUTP levels are high or dUTPase activity is compromised, uracil can be incorporated into DNA; this triggers base-excision repair pathways and, if unrepaired, can lead to mutations or DNA strand breaks.

In molecular biology, dUTP is used intentionally in certain protocols. Replacing dTTP with dUTP in PCR, together with uracil-DNA glycosylase (UNG), allows degradation of any previously amplified uracil-containing DNA, reducing carryover contamination between reactions. dUTP-containing DNA is also used in labeling and post-amplification processing workflows that exploit uracil-directed enzymatic steps.

Synthesis and maintenance of the dUTP pool are tied to broader nucleotide metabolism. dUTP is produced as part of the cellular deoxynucleotide pool, and its steady-state level is governed by dUTPase activity and by the balance with dTTP, which is generated from dUMP via thymidylate synthase.