Carbamoyl-phosphate synthetase large chain, oligomerisation domain
SMART accession number:
SM01096
Description:
Carbamoyl-phosphate synthase catalyses the ATP-dependent synthesis of carbamyl-phosphate from glutamine or ammonia and bicarbonate. The carbamoyl-phosphate synthase (CPS) enzyme in prokaryotes is a heterodimer of a small and large chain.
This entry represents the oligomerisation domain found in the large subunit of carbamoyl phosphate synthases as well as in certain other carboxy phosphate domain-containing enzymes. This domain forms a primarily alpha-helical fold [ (PUBMED:10089390) ].
Family alignment:
There are 32225 CPSase_L_D3 domains in 32224 proteins in SMART's nrdb database.
Click on the following links for more information.
Evolution (species in which this domain is found)
Taxonomic distribution of proteins containing CPSase_L_D3 domain.
This tree includes only several representative species. The complete taxonomic breakdown of all proteins with CPSase_L_D3 domain is also avaliable.
Click on the protein counts, or double click on taxonomic names to display all proteins containing CPSase_L_D3 domain in the selected taxonomic class.
Literature (relevant references for this domain)
Primary literature is listed below; Automatically-derived, secondary literature is also avaliable.
The structure of carbamoyl phosphate synthetase determined to 2.1 Aresolution.
Acta Crystallogr D Biol Crystallogr. 1999; 55: 8-24
Display abstract
Carbamoyl phosphate synthetase catalyzes the formation of carbamoylphosphate from one molecule of bicarbonate, two molecules of Mg2+ATP andone molecule of glutamine or ammonia depending upon the particular form ofthe enzyme under investigation. As isolated from Escherichia coli, theenzyme is an alpha,beta-heterodimer consisting of a small subunit thathydrolyzes glutamine and a large subunit that catalyzes the two requiredphosphorylation events. Here the three-dimensional structure of carbamoylphosphate synthetase from E. coli refined to 2.1 A resolution with an Rfactor of 17.9% is described. The small subunit is distinctly bilobal witha catalytic triad (Cys269, His353 and Glu355) situated between the twostructural domains. As observed in those enzymes belonging to thealpha/beta-hydrolase family, the active-site nucleophile, Cys269, isperched at the top of a tight turn. The large subunit consists of fourstructural units: the carboxyphosphate synthetic component, theoligomerization domain, the carbamoyl phosphate synthetic component andthe allosteric domain. Both the carboxyphosphate and carbamoyl phosphatesynthetic components bind Mn2+ADP. In the carboxyphosphate syntheticcomponent, the two observed Mn2+ ions are both octahedrally coordinated byoxygen-containing ligands and are bridged by the carboxylate side chain ofGlu299. Glu215 plays a key allosteric role by coordinating to thephysiologically important potassium ion and hydrogen bonding to the ribosehydroxyl groups of ADP. In the carbamoyl phosphate synthetic component,the single observed Mn2+ ion is also octahedrally coordinated byoxygen-containing ligands and Glu761 plays a similar role to that ofGlu215. The carboxyphosphate and carbamoyl phosphate synthetic components,while topologically equivalent, are structurally different, as would beexpected in light of their separate biochemical functions.
