Identification of the maltose transport protein of Saccharomyces cerevisiae.

Identification of the maltose transport protein of Saccharomyces cerevisiae was attempted by searching for maltose-inducible proteins in isolated plasma membranes. Membranes from maltose-grown cells contained two proteins that were absent in glucose-grown cells. The proteins differed in size, but peptide sequence analysis indicated a high degree of homology. The amino-terminal and internal sequences of the largest protein, with an apparent molecular mass of 64 kDa, were determined. These sequences were identical to predicted amino acid sequences in the MAL61 gene product. It is concluded that this protein is the inducible maltose permease of Saccharomyces cerevisiae.