Target type: molecularfunction
Catalysis of the reaction: uridine + phosphate = uracil + alpha-D-ribose 1-phosphate. [EC:2.4.2.3]
Uridine phosphorylase activity is a crucial enzymatic process involved in the metabolism of pyrimidine nucleosides, particularly uridine. This activity catalyzes the reversible phosphorolysis of uridine, breaking it down into uracil and ribose 1-phosphate. The reaction involves the transfer of a phosphate group from inorganic phosphate to the ribose moiety of uridine, resulting in the formation of uracil and ribose 1-phosphate. This reaction is significant for several reasons: 1. **Pyrimidine Salvage Pathway:** It plays a key role in the salvage pathway for pyrimidines, allowing the recycling of uracil and ribose 1-phosphate back into usable nucleotides. This pathway conserves cellular energy by avoiding the de novo synthesis of nucleotides from scratch. 2. **Nucleotide Metabolism:** Uridine phosphorylase activity is involved in the interconversion of various pyrimidine nucleosides and nucleotides. It can also contribute to the regulation of nucleotide pools within cells. 3. **Drug Development:** Inhibitors of uridine phosphorylase activity have been investigated as potential therapeutic agents for various diseases. For example, they have been explored for their ability to modulate immune responses and treat certain types of cancer. 4. **Genetic Disorders:** Mutations in the gene encoding uridine phosphorylase can lead to genetic disorders like hereditary orotic aciduria, characterized by an accumulation of orotic acid in the body. Overall, uridine phosphorylase activity is a fundamental enzymatic process that contributes to the overall homeostasis of pyrimidine nucleotides within cells, impacting various cellular processes and metabolic pathways.'
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| Protein | Definition | Taxonomy |
|---|---|---|
| Uridine phosphorylase 1 | A uridine phosphorylase 1 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q16831] | Homo sapiens (human) |
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| doxifluridine | doxifluridine : A pyrimidine 5'-deoxyribonucleoside that is 5-fluorouridine in which the hydroxy group at the 5' position is replaced by a hydrogen. It is an oral prodrug of the antineoplastic agent 5-fluorouracil. Designed to circumvent the rapid degradation of 5-fluorouracil by dihydropyrimidine dehydrogenase in the gut wall, it is converted into 5-fluorouracil in the presence of pyrimidine nucleoside phosphorylase. | organofluorine compound; pyrimidine 5'-deoxyribonucleoside | antimetabolite; antineoplastic agent; prodrug |
| 5-benzylacyclouridine | 5-benzyl-1-(2-hydroxyethoxymethyl)uracil : A pyrimidone that is uracil which is substituted by a 2-hydroxyethoxymethyl group at position 1 and a benzyl group at position 5. 5-benzylacyclouridine: structure given in first source | hydroxyether; primary alcohol; pyrimidone | |
| 3-cyano-6-hydroxy-4-methyl-2-pyridone | 3-cyano-6-hydroxy-4-methyl-2-pyridone: structure in first source | ||
| 2,6-dihydroxy-3-cyanopyridine | 2,6-dihydroxy-3-cyanopyridine: inhibitor of 5-fluorouracil degradation |