Skip to main content
. 2011 Dec 26;2:101. doi: 10.3389/fpls.2011.00101

Figure 1.

Figure 1

The yeast three-hybrid system for target identification. The principle components of the Y3H system are (1) the hook, a fusion protein consisting of a DNA-binding domain and the Mtx-binding enzyme DHFR, (2) the bait, a hybrid ligand of Mtx chemically linked to a small molecule ligand (L) of interest, and (3) the fish, a transcriptional activation domain fused to a protein from a cDNA library (a potential target). The transcriptional activation of the reporter gene (LEU2 or lacZ) only occurs upon formation of the trimeric complex. To validate the Y3H system, the Mtx–Dex hybrid ligand can be used in combination with the high-affinity Dex-binding glucocorticoid receptor (GR) fused to the activation domain. DHFR, dihydrofolate reductase; Mtx, methotrexate.