The FUR1 gene of Saccharomyces cerevisiae: cloning, structure and expression of wild-type and mutant alleles.
The FUR1 gene of Saccharomyces cerevisiae encodes uracil phosphoribosyltransferase (UPRTase) which catalyses the conversion of uracil into uridine 5'-monophosphate (UMP) in the pyrimidine salvage pathway. The FUR1 gene is included in a 2.1 kb genomic segment of DNA and is transcribed into a 1 kb poly(A)+mRNA. Sequencing has determined a 753 bp open reading frame capable of encoding a protein of 251 amino acids. The FUR1 genes for three recessive fur1 alleles, having different sensibilities to 5-fluorouridine (5-FUR) but identical levels of resistance to 5-fluorouracil (5-FU), were cloned and sequenced. Single bp changes located in different regions of the gene were found in each mutant. Two in vitro-constructed deletions of the FUR1 gene have been integrated at the chromosomal locus, giving strains with 5-FURR and 5-FURR mutant phenotype. Assays of UPRTase, uridine kinase, uridine ribohydrolase and uridine 5'-monophosphate nucleotidase enzymatic activities, in extracts of strains where the FUR1 gene is overexpressed or deleted, indicate that the FUR1 encoded protein possesses only UPRTase activity.
Kern
L
L
Laboratoire de Génétique Physiologique, Institut de Biologie Moléculaire et Cellulaire du C.N.R.S., Strasbourg, France.
de Montigny
J
J
Jund
R
R
Lacroute
F
F
D000483:Alleles; D000595:Amino Acid Sequence; D001483:Base Sequence; D002872:Chromosome Deletion; D003001:Cloning, Molecular; D004252:DNA Mutational Analysis; D004274:DNA, Recombinant; D005472:Fluorouracil / Q000378:metabolism; D005800:Genes, Fungal / Q000235:genetics*; D008969:Molecular Sequence Data; D009962:Orotate Phosphoribosyltransferase / Q000235:genetics; D010430:Pentosyltransferases / Q000235:genetics*; D010957:Plasmids; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D014498:Uracil / Q000378:metabolism; D014542:Uridine Monophosphate / Q000378:metabolism
D004274:DNA, Recombinant; D014498:Uracil; D014542:Uridine Monophosphate; D010430:Pentosyltransferases; D009962:Orotate Phosphoribosyltransferase; C023269:uracil phosphoribosyltransferase; D005472:Fluorouracil