CHARACTERIZATION OF THE SACCHAROMYCES-CEREVISIAE RTA1 GENE INVOLVED IN 7-AMINOCHOLESTEROL RESISTANCE

7-aminocholesterol has been described as being a strong inhibitor of y east and of Gram(+)-bacteria proliferation. In order to determine the precise molecular target of the toxicity of this compound, we searched for yeast resistance linked to gene over-expression. We named the new yeast gene that was isolated RT A1 (EMBL X84736). This gene led to st rong resistance to the inhibitor. Gene sequencing revealed that RT A1 is adjacent to the NAB1 gene which is orientated in an opposite direct ion and localized on chromosome VII. The RT A1 gene, which encodes a p utative protein with seven potential membrane-spanning segments, was s hown to be a non-essential gene in yeast.