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EC Number

Catalytic Site Atlas

CSA LITERATURE entry for 1at1

E.C. nameaspartate carbamoyltransferase
SpeciesEscherichia coli (Bacteria)
E.C. Number (IntEnz)
CSA Homologues of 1at1There are 93 Homologs
CSA Entries With UniProtID P0A786
CSA Entries With EC Number
PDBe Entry 1at1
PDBSum Entry 1at1
MACiE Entry 1at1

Literature Report

IntroductionAspartate carbamoyltransferase catalyses the formation of N-carbamoyl-L-aspartate and inorganic phosphate from carbamoyl phosphate and L-aspartate. In many prokaryotes such as E coli this reaction is the committed step in pyrimidine biosynthesis.
MechansimLysine deprotonates the amino group of aspartate to activate it as a nucleophile. Three other residues interact with the carbonyl oxygen of the carbamoyl phosphate, enhancing the electrophilicity of the carbonyl carbon for attack by aspartate. An arginine residue stabilises the developing negative charge of the oxygen as the phosphate leaving group is expelled.

Catalytic Sites for 1at1

Annotated By Reference To The Literature - Site 1 (Perform Site Search)
ResidueChainNumberUniProtKB NumberFunctional PartFunctionTargetDescription
ArgA105106macie:sideChainEnhances electrophilicity of carbonyl carbon.
HisA134135macie:sideChainEnhances electrophilicity of carbonyl carbon.
ThrA5556macie:sideChainEnhances electrophilicity of carbonyl carbon.
LysA8485macie:sideChainDeprotonates the amino group of aspartate.
ArgA5455macie:sideChainStabilises the developing negative charge of the oxygen as the phosphate leaving group is expelled.

Literature References

Jin L
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 37 729-742
PubMed: 10651286