A method to isolate DNA sequences that are promoter-active in Escherichia coli and in yeast.

A method convenient for isolation of DNA sequences capable of directing gene transcription in both organisms of E. coli and yeast is described. The method is composed of sequential steps of phenotypic selection for chloramphenicol resistance, first in E. coli and then in yeast. A series of promoter-probe, shuttle plasmid vectors between yeast and E. coli were constructed and utilized in the method.