4.3. Yeast Library Construction

The cDNA of E20, E26, and E108 was collected according to the manufacturer’s instructions for the CloneMiner II cDNA Library Construction Kit (Invitrogen, Waltham, MA, USA). The cDNA was recombined with pDONR222 and electroporated into DH10B to construct the primary library. The plasmid extracted from the primary library was recombined into pGADT7-DEST and electrotransferred to DH10B to construct a secondary library [33]. The plasmid of the secondary library was extracted. About 5 μg of plasmid DNA was transformed to the yeast strain Y187, and the transformation efficiency was tested by culturing in SD medium lacking leucine (Clontech, Mountain View, CA, USA) [34,35].