Effects of exchanging the second and third Leu residues of the ROXY1 L**LL motif on an interaction with TGA proteins. Quantitative β-galactosidase assays were performed to measure interaction strengths in the yeast two-hybrid system. ROXY1L2I, ROXY1L2M, ROXY1L2T, and ROXY1L2R indicate that the second Leu of the ROXY1 L**LL motif is replaced by an Ile, a Met, a Thr, and an Arg, respectively. ROXY1L3V and ROXY1L3I denote that the third Leu of the ROXY1 L**LL motif is mutated into a Val and an Ile, respectively. Data are means ± sd of three independent experiments.