TY - JOUR
T1 - Use of synthetic lethal mutants to clone and characterize a novel CTP synthetase gene in Saccharomyces cerevisiae
AU - Ozier-Kalogeropoulos, Odile
AU - Adeline, Marie Thérèse
AU - Yang, Weng Lang
AU - Carman, George M.
AU - Lacroute, François
PY - 1994/2
Y1 - 1994/2
N2 - In the pyrimidine biosynthetic pathway, CTP synthetase catalyses the conversion of uridine 5′-triphosphate (UTP) to cytidine 5′-triphosphate (CTP). In the yeast Saccharomyces cerevisiae, the URA7 gene encoding this enzyme was previously shown to be nonessential for cell viability. The present paper describes the selection of synthetic lethal mutants in the CTP biosynthetic pathway that led us to clone a second gene, named URA8, which also encodes a CTP synthetase. Comparison of the predicted amino acid sequences of the products of URA7 and URA8 shows 78% identity. Deletion of the URA8 gene is viable in a haploid strain but simultaneous presence of null alleles both URA7 and URA8 is lethal. Based on the codon bias values for the two genes and the intracellular concentrations of CTP in strains deleted for one of the two genes, relative to the wild-type level, URA7 appears to be the major gene for CTP biosynthesis. Nevertheless, URA8 alone also allows yeast growth, at least under standard laboratory conditions.
AB - In the pyrimidine biosynthetic pathway, CTP synthetase catalyses the conversion of uridine 5′-triphosphate (UTP) to cytidine 5′-triphosphate (CTP). In the yeast Saccharomyces cerevisiae, the URA7 gene encoding this enzyme was previously shown to be nonessential for cell viability. The present paper describes the selection of synthetic lethal mutants in the CTP biosynthetic pathway that led us to clone a second gene, named URA8, which also encodes a CTP synthetase. Comparison of the predicted amino acid sequences of the products of URA7 and URA8 shows 78% identity. Deletion of the URA8 gene is viable in a haploid strain but simultaneous presence of null alleles both URA7 and URA8 is lethal. Based on the codon bias values for the two genes and the intracellular concentrations of CTP in strains deleted for one of the two genes, relative to the wild-type level, URA7 appears to be the major gene for CTP biosynthesis. Nevertheless, URA8 alone also allows yeast growth, at least under standard laboratory conditions.
KW - CTP synthetase
KW - Duplicate genes
KW - Pyrimidine biosynthetic pathway
KW - Saccharomyces cerevisiae
KW - Synthetic lethal mutants
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U2 - 10.1007/BF00281793
DO - 10.1007/BF00281793
M3 - Article
C2 - 8121398
AN - SCOPUS:0028220510
SN - 0026-8925
VL - 242
SP - 431
EP - 439
JO - MGG Molecular & General Genetics
JF - MGG Molecular & General Genetics
IS - 4
ER -