One of 9 shuttle vectors (ATCC# 87585 ​ 87593) allowing lacZ detection of cloned inserts and containing the pUC 19 MCS with all 10 cloning sites unique. Vectors differ in mode of replication (YE, YC or YI­type) and yeast marker (LEU2, URA3 or TRP1). This vector is a YI­type (yeast integrating)one with the URA3 yeast marker. The PstI restriction site from the URA3 gene of S. cerevisiae was removed by using oligo­directed mutagenesis.