title: Characterization of the Saccharomyces cerevisiae FCY1 gene encoding cytosine deaminase and its homologue FCA1 of Candida albicans.
abstract: By functional complementation of a fcy1 null mutant of Saccharomyces cerevisiae, we have cloned and characterized the FCY1 gene, encoding cytosine deaminase in Saccharomyces cerevisiae, and its homologue FCA1, encoding cytosine deaminase in Candida albicans. Disruption of FCY1 resulted in high resistance to 5-fluorocytosine (10(-2) M) and in total loss of cytosine deaminase activity. By contrast the transformation by FCY1 or FCA1 of the haploid FCY1-disrupted host strain restored sensitivity to 5-fluorocytosine and allowed growth on cytosine, as a source of pyrimidine, or ammonium. FCA1 as opposed to FCY1 contains an intron. FCA1 and FCY1 encode respectively 150- and 158- residue proteins of 60% identity. Both Fcy1p and Fca1p share common motifs with cytidine and CMP deaminases, but homology with cytosine deaminase of E. coli could not be detected.
authors.affiliation: Laboratoire de génétique, UPR 9003 CNRS, Institut de Recherche contre les Cancers de l'Appareil Digestif (IRCAD), Hospices Civils, 1, place de l'hôpital, F-67091 Strasbourg Cedex, France.
authors.forename: P
authors.initials: P
authors.lastname: Erbs
authors.forename: F
authors.initials: F
authors.lastname: Exinger
authors.forename: R
authors.initials: R
authors.lastname: Jund
mesh_terms: D000595:Amino Acid Sequence; D002176:Candida albicans / Q000235:genetics*; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D003596:Cytosine / Q000378:metabolism; D043525:Cytosine Deaminase; D004271:DNA, Fungal / Q000032:analysis; D004926:Escherichia coli / Q000235:genetics; D005437:Flucytosine / Q000494:pharmacology; D015971:Gene Expression Regulation, Enzymologic; D015966:Gene Expression Regulation, Fungal; D015723:Gene Library; D005816:Genetic Complementation Test; D007438:Introns; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D009700:Nucleoside Deaminases / Q000235:genetics* / Q000378:metabolism; D010957:Plasmids; D015183:Restriction Mapping; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014170:Transformation, Genetic
chemical_list: D004271:DNA, Fungal; D003596:Cytosine; D005437:Flucytosine; D009700:Nucleoside Deaminases; D043525:Cytosine Deaminase