ISOLATION OF A NEW GENE (SWA2) ENCODING AN ALPHA-AMYLASE FROM SCHWANNIOMYCES-OCCIDENTALIS AND ITS EXPRESSION IN SACCHAROMYCES-CEREVISIAE

A new gene (SW A2) encoding a secretory alpha-amylase activity from Schwanniomyces occidentalis has been cloned from this yeast and then expressed in Saccharomyces cerevisiae. Both Sw. occidentalis and a transformant of S. cerevisiae incorporating SW A2 contain a transcript of 2.1 kb which hybridizes to DNA carrying the SW A2 gene. This indicates that the transcript is a product of the SW A2 gene. Transcription of the SW A2 gene seems to be regulated in both Sw. occidentalis and S. cerevisiae. Furthermore, the secretion of alpha-amylase activity is drastically repressed by glucose in both Sw. occidentalis and a transformant of S. cerevisiae containing SW A2.