pyrimidine nucleobase metabolic process

Definition

Target type: biologicalprocess

The chemical reactions and pathways involving pyrimidine nucleobases, 1,3-diazine, organic nitrogenous bases. [GOC:go_curators]

Pyrimidine nucleobase metabolic process is a fundamental biological process responsible for the synthesis, modification, and degradation of pyrimidine nucleobases, essential building blocks of DNA and RNA. This process involves a series of enzymatic reactions that convert simple precursor molecules into complex pyrimidine nucleobases, such as cytosine, thymine, and uracil. These nucleobases are then incorporated into nucleotides, which in turn form the backbone of DNA and RNA, carrying the genetic code and playing crucial roles in cellular functions like replication, transcription, and translation. The pyrimidine metabolic pathway begins with the synthesis of the precursor molecule, carbamoyl phosphate, from glutamine and bicarbonate. Carbamoyl phosphate then reacts with aspartate to form carbamoyl aspartate, which is subsequently converted into dihydroorotate. Dihydroorotate is then oxidized to orotate, which undergoes a series of reactions to form the pyrimidine nucleotide, uridine monophosphate (UMP). UMP can be further phosphorylated to UDP and UTP, which serve as precursors for the synthesis of other pyrimidine nucleotides, such as cytidine triphosphate (CTP) and thymidine triphosphate (TTP). The degradation of pyrimidine nucleobases occurs primarily in the liver, where they are converted to β-alanine, β-aminoisobutyrate, or uracil. These degradation products are then excreted in urine. Disruptions in pyrimidine metabolism can lead to a variety of genetic diseases, including orotic aciduria, which is characterized by an accumulation of orotic acid in the urine, and pyrimidine nucleoside phosphorylase deficiency, which causes a buildup of pyrimidine nucleosides in the blood and tissues. These disorders can lead to various clinical manifestations, including developmental delays, immune deficiencies, and neurological dysfunction.'
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Proteins (3)

Compounds (29)