As in Saccharomyces cerevisiae, aspartate transcarbamoylase is assembled on a multifunctional protein including a dihydroorotase-like cryptic domain in Schizosaccharomyces pombe.
The organisation of the URA1 gene of Schizosaccharomyces pombe was determined from the entire cDNA cloned by the transformation of an ATCase-deficient strain of Saccharomyces cerevisiae. The URA1 gene encodes the bifunctional protein GLNase/CPSase-ATCase which catalyses the first two steps of the pyrimidine biosynthesis pathway. The complete nucleotide sequence of the URA1 cDNA was elucidated and the deduced amino-acid sequence was used to define four domains in the protein; three functional domains, corresponding to GLNase (glutamine amidotransferase), CPSase (carbamoylphosphate synthetase) and ATCase (aspartate transcarbamoylase) activities, and one cryptic DHOase (dihydroorotase) domain. Genetic investigations confirmed that both GLNase/CPSase and ATCase activities are carried out by the same polypeptide. They are also both feedback-inhibited by UTP (uridine triphosphate). Its organization and regulation indicate that the S. pombe URA1 gene product appears very similar to the S. cerevisiae URA2 gene product.
Lollier
M
M
Laboratoire de Microbiologie et de Génétique, URA n-1481 Université Louis-Pasteur/CNRS, Strasbourg, France.
Jaquet
L
L
Nedeva
T
T
Lacroute
F
F
Potier
S
S
Souciet
J L
JL
D000595:Amino Acid Sequence; D000878:Anthranilate Synthase; D001221:Aspartate Carbamoyltransferase / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D002223:Carbamoyl-Phosphate Synthase (Glutamine-Hydrolyzing) / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D004271:DNA, Fungal; D004080:Dihydroorotase / Q000378:metabolism*; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D019884:Nitrogenous Group Transferases; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D012568:Schizosaccharomyces / Q000201:enzymology / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D014166:Transferases / Q000378:metabolism; D014544:Uridine Triphosphate / Q000378:metabolism
D004271:DNA, Fungal; D009097:Multienzyme Complexes; C019820:carbamoyl phosphate synthase-aspartatecarbamoyl transferase complex; D014166:Transferases; D001221:Aspartate Carbamoyltransferase; D019884:Nitrogenous Group Transferases; D004080:Dihydroorotase; D000878:Anthranilate Synthase; C020655:anthranilate synthase, glutamine amidotransferase subunit; D002223:Carbamoyl-Phosphate Synthase (Glutamine-Hydrolyzing); D014544:Uridine Triphosphate