| Type: | Family | Name: | Aspartate carbamoyltransferase |
| Description: | Aspartate carbamoyltransferase (ATCase) catalyses the formation of carbamoyl-aspartate in the pyrimidine biosynthesis pathway, by the association of aspartate and carbamoyl-phosphate. This is the commitment step in the Escherichia colipathway and is regulated by feedback inhibition by CTP, the final product of the pathway [].The structural organisation of the ATCase protein varies considerably between different organisms. In bacteria such as E. coli, Salmonella typhimuriumand Serratia marcescens, the ATCase is a dodecamer of 2 catalytic (c) trimers and 3 regulatory (r) dimers. The catalytic domains are coded for by thepyrB gene [], and the regulatory domains by pyrI []. In Gram-positive bacteriasuch as Bacillus subtilis, ATCase exists as a trimer of catalytic subunits, but unlike in E. coli, it neither contains nor binds to regulatory subunits. Ineukaryotes, ATCase is found as a single domain in a multifunctional enzyme that contains activity for glutamine amidotransferase, carbamoylphosphatesynthetase, dihydroorotase, and aspartate carbamoyltransferase. | Short Name: | Asp_carbamoyltransf |
