Open AccessFusion of the Saccharomyces cerevisiae leu2 gene to an Escherichia coli beta-galactosidase gene.
Author(s) -
Alfonso Martínez-Arias,
Malcolm J. Casadaban
Publication year - 1983
Publication title -
molecular and cellular biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.14
H-Index - 327
eISSN - 1067-8824
pISSN - 0270-7306
DOI - 10.1128/mcb.3.4.580
Subject(s) - biology , escherichia coli , saccharomyces cerevisiae , mutant , beta galactosidase , gene product , gene , fusion gene , microbiology and biotechnology , yeast , plasmid , chimeric gene , gene expression , biochemistry
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.