Synthesis of Escherichia coli outer membrane ompA protein in yeasts

Saccharomyces cerevisiae was transformed with the Escherichia coli ompA gene coding for an outer membrane protein. Yeast transformants containing the pYTU101 plasmid, consisting of the ompA gene cloned in pSC101 and the HindIII-3 fragment of 2-microns DNA, express the foreign membrane protein. The protein synthesized in yeast has an Mr value very similar if not identical to that of the mature E. coli protein. The expressed protein is present in yeast mitochondrial and plasma membrane fractions. The yeast cell can tolerate about 250 molecules of the foreign membrane protein per cell, although the transformants show altered growth kinetics.