Yeast expression systems with vectors having PyK promoters, and synthesis of foreign protein.

摘要

Yeast cells containing DNA plasmids having foreign DNA, wherein foreign DNA is expressed, are described. For example, DNA coding for hepatitis B and its virus surface antigen (HBsAg) is ligated to a yeast plasmid to yield a product that is used to transform yeast cells. the plasmids of this invention have PyK promoters, and are capable of replicating in either a yeast cell or a bacterial cell.