aspartate carbamoyltransferase

enzyme

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June 18, 2026

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Aspartate carbamoyltransferase (ATCase) is an enzyme that catalyzes the first step in the biosynthesis of pyrimidine nucleotides, which are essential components of DNA and RNA. This enzyme plays a crucial role in regulating metabolism by controlling the production of these nucleotides.1

ATCase is subject to end-product inhibition, meaning that when the cell has sufficient pyrimidine nucleotides, such as CTP, the enzyme's activity is reduced. This inhibition is overcome by the presence of purine nucleotides like ATP, which are also needed for nucleic acid synthesis. This regulatory mechanism ensures a balanced supply of both purine and pyrimidine precursors for cellular needs.1

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metabolism
End-product inhibition
Studies of aspartate carbamoyltransferase have revealed that the affinity of this enzyme for its substrate (aspartate) is markedly decreased by the presence of CTP. This effect can be overcome by the addition of ATP, a purine nucleotide. The enzyme can be dissociated into two subunits: one contains…
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Studies of aspartate carbamoyltransferase have revealed that the affinity of this enzyme for its substrate (aspartate) is markedly decreased by the presence of CTP. This effect can be overcome by the addition of ATP, a purine nucleotide. The enzyme can be dissociated into two subunits: one contains…
Read More