EcoliHub logo

Try the new EcoliHub and let us know what you'd like to see.

carbamoyl phosphate synthetase

From EcoliWiki

Jump to: navigation, search

About

Description (originally from EcoCyc[1][2]) carbamoyl phosphate synthetase

Comments (originally from EcoCyc[1][2]) Carbamoyl phosphate synthase catalyzes reactions in the biosynthesis of pyrimidine nucleotides and arginine. The enzyme is a tetramer of heterodimers. The small subunit has amidotransferase activity and the large subunit has synthetase activity.

The assembly of carbamoyl phosphate requires at least four separate chemical reactions: phosphorylation of bicarbonate to carboxyphosphate; hydrolization of glutamine to glutamate and ammonia; a nucleophilic attack of ammonia on carboxyphosphate yielding carbamate; and finally the phosphorylation of carbamate forming carbamoyl phosphate.

In addition to the Mg+2 needed to complex with the nucleotide substrate, free Mg+2 is an absolute requirement for activity. Other ions also bind at the divalent cation site and the nucleotide site. [3][4]


References

  1. 1.0 1.1 EcoCyc (release 10.6; 2007) Keseler, IM et al. (2005) Nucleic Acids Res. 33(Database issue):D334-7
  2. 2.0 2.1 EcoCyc (release 11.1; 2007) Keseler, IM et al. (2005) Nucleic Acids Res. 33(Database issue):D334-7
  3. Raushel FM et al. (1979) Paramagnetic probes for carbamoyl-phosphate synthetase: metal ion binding studies and preparation of nitroxide spin-labeled derivatives. Biochemistry 18: 5562-6 PubMed EcoliWiki page
  4. Thoden JB et al. (1999) The structure of carbamoyl phosphate synthetase determined to 2.1 A resolution. Acta Crystallogr D Biol Crystallogr 55: 8-24 PubMed EcoliWiki page

Pages in category "Complex:carbamoyl phosphate synthetase"

The following 2 pages are in the current category.

C


Personal tools