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MS
rate-limiting unreviewed

CPS-II domain of carbamoyl-phosphate synthetase II (CPS-II)

1 reactions · 1 pathways

What it does, reaction by reaction

1 reactions

Pyrimidine De Novo Synthesis (through to UMP, then CTP/dTMP) Nucleotide Metabolism · Cytosol (one mitochondrial step)

step 1 Irreversible rate-limiting

Glutamine + bicarbonate → carbamoyl phosphate

Converts Glutamine HCO3- into Carbamoyl phosphate

Notes

The CPS-II domain of carbamoyl-phosphate synthetase II (CPS-II) catalyzes glutamine + HCO3− + 2 ATP + H2O → carbamoyl phosphate + glutamate + 2 ADP + Pi. One ATP activates bicarbonate and a second phosphorylates carbamate; ammonia generated in the glutaminase domain is channeled internally. This cytosolic reaction is the committed, rate-limiting, and effectively irreversible step of mammalian pyrimidine de novo synthesis; it must not be confused with mitochondrial CPS-I of the urea cycle.

Showing all 1 reactions.

What accelerates and inhibits it

Regulation is pathway-specific, so each context is listed separately

0 entries

No regulation recorded for this enzyme in the source documents.

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