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.