To construct plasmid YEp-3X, pEGFP-N1-AXYL1 and pUC18-
PXYL2 were digested by BamHI-XhoI and PstI-BamHI, respectively,
and then the resulting 2.0 kb and 2.2 kb fragments were inserted
into the corresponding restriction sites of plasmid YEplac195-
PXKS1 to form plasmid YEp-3X.
PXKS1.