CATH Classification

Domain Context

CATH Clusters

Superfamily Methylglyoxal synthase-like domain
Functional Family Carbamoyl-phosphate synthase large chain

Enzyme Information

6.3.5.5
Carbamoyl-phosphate synthase (glutamine-hydrolyzing).
based on mapping to UniProt P00968
2 ATP + L-glutamine + HCO(3)(-) + H(2)O = 2 ADP + phosphate + L-glutamate + carbamoyl phosphate.
-!- The product carbamoyl phosphate is an intermediate in the biosynthesis of arginine and the pyrimidine nucleotides. -!- The enzyme from Escherichia coli has three separate active sites, which are connected by a molecular tunnel that is almost 100 A in length. -!- The amidotransferase domain within the small subunit of the enzyme hydrolyzes glutamine to ammonia via a thioester intermediate. -!- The ammonia migrates through the interior of the protein, where it reacts with carboxyphosphate to produce the carbamate intermediate. -!- The carboxyphosphate intermediate is formed by the phosphorylation of hydrogencarbonate by ATP at a site contained within the N-terminal half of the large subunit. -!- The carbamate intermediate is transported through the interior of the protein to a second site within the C-terminal half of the large subunit, where it is phosphorylated by another ATP to yield the final product, carbamoyl phosphate. -!- Cf. EC 6.3.4.16. -!- Formerly EC 2.7.2.9.

UniProtKB Entries (1)

P0A6F1
CARA_ECOLI
Escherichia coli K-12
Carbamoyl-phosphate synthase small chain

PDB Structure

PDB 1A9X
External Links
Method X-RAY DIFFRACTION
Organism Escherichia
Primary Citation
Carbamoyl phosphate synthetase: caught in the act of glutamine hydrolysis.
Thoden, J.B., Miran, S.G., Phillips, J.C., Howard, A.J., Raushel, F.M., Holden, H.M.
Biochemistry