pYES2/NT A, B, and C and pYC2/NT A, B, and C are 6.0 kb and 4.7 kb vectors,respectively, designed for inducible expression of recombinant proteins in Saccharomyces cerevisiae. Features of the vectors allow purification and detection of expressed proteins. 
The vectors contain the following elements:
? Yeast GAL1 promoter for high level inducible protein expression in yeast by galactose and repression by glucose (Giniger et al., 1985; West et al., 1984).
? Three reading frames to facilitate in-frame cloning with an N-terminal peptide encoding the Xpress? epitope and a polyhistidine (6xHis) tag.
? C-terminal peptide encoding the V5 epitope and a polyhistidine tag for purification and detection of a recombinant fusion protein, if desired.
? 2μ origin (pYES2/NT only) for episomal maintenance and high copy replication of the plasmid in yeast.
? CEN6/ARSH4 sequence (pYC2/NT only) for non-integrative centromeric maintenance and low copy replication of the plasmid in yeast.
? URA3 auxotrophic marker for selection of yeast transformants.
? Ampicillin resistance gene for selection in E. coli.