title: Carbamyl-phosphate synthetase domain of the yeast multifunctional protein Ura2 is necessary for aspartate transcarbamylase inhibition by UTP.
abstract: In Saccharomyces cerevisiae, the first two reactions of pyrimidine biosynthesis are catalyzed by the multifunctional protein Ura2 carrying both carbamyl-phosphate synthetase (CPSase) and aspartate transcarbamylase (ATCase) enzyme activities. In order to study how UTP regulates both of these activities mutant strains were constructed: one strain which expressed the Ura2 protein fused to the green fluorescent protein, and two strains expressed truncated Ura2 proteins. These strains exhibited a phenotype associated with a modified regulation of the pyrimidine pathway. Results presented in this report provide arguments in favor of a single UTP binding site located on the CPSase domain, and support a model in which ATCase activity is inhibited by UTP only when it can interact with the CPSase domain.
authors.affiliation: Département de Génie Biochimique, URA-CNRS 544, Institut National des Sciences Appliquées, Complexe scientifique de Rangueil, Toulouse, France.
authors.forename: R
authors.initials: R
authors.lastname: Antonelli
authors.forename: L
authors.initials: L
authors.lastname: Estevez
authors.forename: M
authors.initials: M
authors.lastname: Denis-Duphil
mesh_terms: D001221:Aspartate Carbamoyltransferase / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000378:metabolism*; D001665:Binding Sites; D002223:Carbamoyl-Phosphate Synthase (Glutamine-Hydrolyzing) / Q000096:biosynthesis / Q000378:metabolism*; D049452:Green Fluorescent Proteins; D007700:Kinetics; D008164:Luminescent Proteins / Q000096:biosynthesis / Q000378:metabolism; D009097:Multienzyme Complexes / Q000096:biosynthesis / Q000378:metabolism*; D010641:Phenotype; D011743:Pyrimidines / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D029701:Saccharomyces cerevisiae Proteins; D014544:Uridine Triphosphate / Q000494:pharmacology*
chemical_list: D008164:Luminescent Proteins; D009097:Multienzyme Complexes; D011743:Pyrimidines; D029701:Saccharomyces cerevisiae Proteins; C110837:URA2 protein, S cerevisiae; D049452:Green Fluorescent Proteins; D001221:Aspartate Carbamoyltransferase; D002223:Carbamoyl-Phosphate Synthase (Glutamine-Hydrolyzing); D014544:Uridine Triphosphate