Isolation and expression in Saccharomyces cerevisiae of a gene encoding an α‐amylase from Schwanniomyces castellii

Abstract
A gene (SWA1) encoding an α‐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 α‐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.