[Regulation of yeast gene Leu 2 expression in Escherichia coli by IS1 element].

Expression of the yeast LEU2 gene in Escherichia coli is not sufficiently high. That is why the growth rate of leuB E. coli transformants slowed down on media lacking leucine. The mutations leading to the increase in yeast gene expression in bacteria were found. It has been shown that mutations are connected with insertion of the bacterial IS1 element into the regulatory region of LEU2. The increase in the yeast gene expression does not depend on orientation of the inserted IS1 element. The IS1 element insertion seems to control the attenuation of transcription of LEU2.