Mapping the PHD3 binding domain of ATF-4. (A) Schematic drawing of the protein domains of ATF-4. Arrows (27, 42, 51, and 83) indicate the insertion of the 4 independent ATF-4 prey-clones identified by yeast 2-hybrid screening of the human brain cDNA library with PHD3 as bait. (B) Yeast reporter strain MaV203 expressing Gal4-BD-PHD3 and various domains of ATF-4 as Gal4-AD-fusions was assayed for histidine and uracil auxotrophy. (C) Yeast reporter strain MaV203 expressing Gal4-BD-PHD3 and various deletion variants of ATF-4 as Gal4-AD fusions was assayed for histidine and uracil auxotrophy.