Investigation of P6-P9-1 interaction in YTH system. (A) Yeast colonies containing pGBKT7-P9-1/pGADT7-P6 grew well on the selective medium, whereas the yeast transformed with pGBKT7-P9-1 and pGADT7, used as a negative control, was unable to grow. (B) Yeast colonies expressing BD-P9-1 with AD-P6341-792, AD-P6274-703, AD-P6271-703, AD-P6395-703, or AD-P6395-659 grew well on the selective medium, but those expressing BD-P9-1 with AD-P61-449 did not. The numbers denote P6 amino acid positions. (C) Yeast colonies expressing AD-P6 with any of the P9-1 mutants fused with BD domain showed no growth on the selective medium. The numbers denote P9-1 amino acid positions.