Deoxyuridine

Deoxyuridine is a nucleoside, a type of molecule that is a building block of DNA. It consists of the pyrimidine nucleobase uracil and the deoxyribose sugar. In DNA, uracil is typically replaced by thymine, but deoxyuridine can be incorporated into DNA under certain conditions, particularly during DNA replication or repair processes.

The presence of deoxyuridine in DNA can have implications for genome stability. Enzymes known as uracil-DNA glycosylases are responsible for recognizing and removing deoxyuridine from DNA, preventing its accumulation and potential for causing mutations. If deoxyuridine is not efficiently removed, it can lead to errors during DNA replication, where adenine might pair with uracil instead of thymine, resulting in base substitutions.

Deoxyuridine plays a role in cellular metabolism and is involved in the synthesis of thymidine, a crucial component of DNA. The enzyme thymidylate synthase catalyzes the conversion of deoxyuridine monophosphate (dUMP) to deoxythymidine monophosphate (dTMP), effectively producing thymine for DNA. Disruptions in this pathway can have significant consequences for cell division and DNA integrity. Deoxyuridine itself is not a standard component of RNA, which uses ribose sugar and uracil.