1ce8

CARBAMOYL PHOSPHATE SYNTHETASE FROM ESCHERICHIS COLI WITH COMPLEXED WITH THE ALLOSTERIC LIGAND IMP

spinqualitylabelsall models 1ce8, resolution 2.10Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1ce8 is a 8 chain structure with sequence from "bacillus_coli"_migula_1895 "bacillus coli" migula 1895. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: ADP, CL, IMP, K, MN, NET, ORN, PO4 Activity: Carbamoyl-phosphate synthase (glutamine-hydrolyzing), with EC number 6.3.5.5 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed Carbamoyl phosphate synthetase (CPS) from Escherichia coli catalyzes the formation of carbamoyl phosphate, which is subsequently employed in both the pyrimidine and arginine biosynthetic pathways. The reaction mechanism is known to proceed through at least three highly reactive intermediates: ammonia, carboxyphosphate, and carbamate. In keeping with the fact that the product of CPS is utilized in two competing metabolic pathways, the enzyme is highly regulated by a variety of effector molecules including potassium and ornithine, which function as activators, and UMP, which acts as an inhibitor. IMP is also known to bind to CPS but the actual effect of this ligand on the activity of the enzyme is dependent upon both temperature and assay conditions. Here we describe the three-dimensional architecture of CPS with bound IMP determined and refined to 2.1 A resolution. The nucleotide is situated at the C-terminal portion of a five-stranded parallel beta-sheet in the allosteric domain formed by Ser(937) to Lys(1073). Those amino acid side chains responsible for anchoring the nucleotide to the polypeptide chain include Lys(954), Thr(974), Thr(977), Lys(993), Asn(1015), and Thr(1017). A series of hydrogen bonds connect the IMP-binding pocket to the active site of the large subunit known to function in the phosphorylation of the unstable intermediate, carbamate. This structural analysis reveals, for the first time, the detailed manner in which CPS accommodates nucleotide monophosphate effector molecules within the allosteric domain. The binding of inosine monophosphate to Escherichia coli carbamoyl phosphate synthetase.,Thoden JB, Raushel FM, Wesenberg G, Holden HM J Biol Chem. 1999 Aug 6;274(32):22502-7. PMID:10428826 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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