D
IPR006132

Aspartate/ornithine carbamoyltransferase, carbamoyl-P binding

InterPro entry
Short nameAsp/Orn_carbamoyltranf_P-bd
Overlapping
homologous
superfamilies
 

Description

This entry contains two related enzymes:
     * Aspartate carbamoyltransferase (
2.1.3.2
) (ATCase) catalyzes the conversion of aspartate and carbamoyl phosphate to carbamoylaspartate, the second step in thede novo biosynthesis of pyrimidine nucleotides
[1]
. In prokaryotes ATCase consists of two subunits: a catalytic chain (gene pyrB) and a regulatory chain (gene pyrI), while in eukaryotes it is a domain in a multi- functional enzyme (called URA2 in yeast, rudimentary in Drosophila, and CAD in mammals
[2]
) that also catalyzes other steps of the biosynthesis of pyrimidines.
 * Ornithine carbamoyltransferase (
2.1.3.3
) (OTCase) catalyzes the conversion of ornithine and carbamoyl phosphate to citrulline. In mammals this enzyme participates in the urea cycle
[3]
and is located in the mitochondrial matrix. In prokaryotes and eukaryotic microorganisms it is involved in the biosynthesis of arginine. In some bacterial species it is also involved in the degradation of arginine
[4]
(the arginine deaminase pathway).
It has been shown
[5]
that these two enzymes are evolutionary related. The predicted secondary structure of both enzymes are similar and there are some regions of sequence similarities. One of these regions includes three residues which have been shown, by crystallographic studies
[6]
, to be implicated in binding the phosphoryl group of carbamoyl phosphate and may also play a role in trimerization of the molecules
[7]
. The carboxyl-terminal, aspartate/ornithine-binding domain is is described by
IPR006131
.

References

1.Cloning and structure of the Bacillus subtilis aspartate transcarbamylase gene (pyrB). Lerner CG, Switzer RL. J. Biol. Chem. 261, 11156-65, (1986). View articlePMID: 3015959

2.The evolutionary history of the first three enzymes in pyrimidine biosynthesis. Davidson JN, Chen KC, Jamison RS, Musmanno LA, Kern CB. Bioessays 15, 157-64, (1993). View articlePMID: 8098212

3.Evolutionary aspects of urea cycle enzyme genes. Takiguchi M, Matsubasa T, Amaya Y, Mori M. Bioessays 10, 163-6, (1989). View articlePMID: 2662961

4.Primary and quaternary structure of the catabolic ornithine carbamoyltransferase from Pseudomonas aeruginosa. Extensive sequence homology with the anabolic ornithine carbamoyltransferases of Escherichia coli. Baur H, Stalon V, Falmagne P, Luethi E, Haas D. Eur. J. Biochem. 166, 111-7, (1987). View articlePMID: 3109911

5.Protein differentiation: a comparison of aspartate transcarbamoylase and ornithine transcarbamoylase from Escherichia coli K-12. Houghton JE, Bencini DA, O'Donovan GA, Wild JR. Proc. Natl. Acad. Sci. U.S.A. 81, 4864-8, (1984). View articlePMID: 6379651

6.Structure of unligated aspartate carbamoyltransferase of Escherichia coli at 2.6-A resolution. Ke HM, Honzatko RB, Lipscomb WN. Proc. Natl. Acad. Sci. U.S.A. 81, 4037-40, (1984). View articlePMID: 6377306

7.Assessment of the allosteric mechanism of aspartate transcarbamoylase based on the crystalline structure of the unregulated catalytic subunit. Beernink PT, Endrizzi JA, Alber T, Schachman HK. Proc. Natl. Acad. Sci. U.S.A. 96, 5388-93, (1999). View articlePMID: 10318893

GO terms

Cross References

Contributing Member Database Entry
This website requires cookies, and the limited processing of your personal data in order to function. By using the site you are agreeing to this as outlined in our Privacy Notice and Terms of Use.