Isolation and expression in Saccharomyces cerevisiae of a gene encoding an alpha-amylase from Schwanniomyces castellii.

A gene (SWA1) encoding an alpha-amylase activity from Schwanniomyces castellii has been cloned and expressed, via yeast cloning vector YEp13, in Saccharomyces cerevisiae. By using a riboprobe which is internal to the SWA1 gene, a 1.55 kb transcript was detected in the poly(A)+ RNA from both Sw. castellii and a S. cerevisiae clone harboring the SWA1 gene. This transcript should, therefore, correspond to the SWA1 gene. In addition, the DNA strand determining the alpha-amylase activity has been defined. Transcription of the SWA1 gene appears to be highly regulated in Sw. castellii, whereas it is constitutive in the S. cerevisiae harboring this gene.