Aspartate carbamoyltransferase

Function

Aspartate carbamoyltransferase (ATC) is part of the pyrimidine biosynthesis pathway. ATC catalyzes the condensation of aspartate and carbamoyl phosphate to N-carbamyl-L-aspartate and phosphate. The Zn atom is essential for the association of the subunits. Binding of the substrate to the catalytic subunits results in a high-affinity state while binding of CTP to the regulatory subunit results in a low-affinity state. Malate and phosphonoacetyl-L-aspartate (PALA) are inhibitors of ATC. For additional details see Aspartate Transcarbamoylase (ATCase).

Structural highlights

ATC is composed of . Click to see and . The contains an and a carbamoyl-phosphate-binding domain. The regulatory subunit contains a nucleotide effectors-binding domain and a zinc domain. ^[1]

3D structures of aspartate carbamoyltransferase

Aspartate carbamoyltransferase 3D structures

Structure of E. coli aspartate carbamoyltransferase catalytic (cyan and pink) and regulatory (green and yellow) subunits complex with inhibitor PALA and Zn+2 ions (grey) (PDB code 1d09).

Drag the structure with the mouse to rotate

ReferencesReferences

↑ Jin L, Stec B, Lipscomb WN, Kantrowitz ER. Insights into the mechanisms of catalysis and heterotropic regulation of Escherichia coli aspartate transcarbamoylase based upon a structure of the enzyme complexed with the bisubstrate analogue N-phosphonacetyl-L-aspartate at 2.1 A. Proteins. 1999 Dec 1;37(4):729-42. PMID:10651286

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Michal Harel, Alexander Berchansky, Joel L. Sussman

[1] Jin L, Stec B, Lipscomb WN, Kantrowitz ER. Insights into the mechanisms of catalysis and heterotropic regulation of Escherichia coli aspartate transcarbamoylase based upon a structure of the enzyme complexed with the bisubstrate analogue N-phosphonacetyl-L-aspartate at 2.1 A. Proteins. 1999 Dec 1;37(4):729-42. PMID:10651286

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