Fusion of the Saccharomyces cerevisiae leu2 gene to an Escherichia coli beta-galactosidase gene.
The promoter and translation initiation region of the Saccharomyces cerevisiae leu2 gene was fused to the Escherichia coli beta-galactosidase gene. This fusion located the control region of the leu gene and orientated its direction of expression. When the fusion was placed into yeast cells, beta-galactosidase was expressed under the same regulatory pattern as the original leu2 gene product: its synthesis was repressed in the presence of leucine and threonine. Sensitive chromogenic substrates for beta-galactosidase were used to detect expression in isolated colonies growing on agar medium. Mutant yeast cells with increased beta-galactosidase activity were identified by the color of the colonies they formed. One class of mutants obtained appeared to affect ars1 plasmid maintenance, and another class appeared to affect beta-galactoside uptake.
D050539:3-Isopropylmalate Dehydrogenase; D000429:Alcohol Oxidoreductases / Q000235:genetics*; D004274:DNA, Recombinant; D004926:Escherichia coli / Q000235:genetics*; D005696:Galactosidases / Q000235:genetics*; D005786:Gene Expression Regulation; D007930:Leucine / Q000235:genetics*; D009154:Mutation; D010957:Plasmids; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D001616:beta-Galactosidase / Q000235:genetics*
D004274:DNA, Recombinant; D000429:Alcohol Oxidoreductases; D050539:3-Isopropylmalate Dehydrogenase; D005696:Galactosidases; D001616:beta-Galactosidase; D007930:Leucine