Sequence Motifs in MADS Transcription Factors Responsible for Specificity and Diversification of Protein-Protein Interaction
Figure 2
Example of the experimental validation approach.
(A) Schematic representation of the SUPPRESSOR OF OVEREXPRESSION OF CO 1 (SOC1) and AGAMOUS LIKE14 (AGL14) MADS domain proteins. Due to the generated mutations one particular interaction motif (green rectangle) is swapped between these two Arabidopsis MADS domain transcription factors. The swapped motif is located in the “hotspot” region between the MADS and I-domain. (B) Part of a sequence alignment of AGL14 and SOC1, including the motif that was selected for mutagenesis (indicated in green in the SOC1 sequence). The mutated residues that were swapped between the two proteins are shown bold/underlined. (C) Bar diagrams showing the number of interaction partners for SOC1, AGL14 and their mutated counterparts SOC1* and AGL14*, respectively; see Table 1. For these two proteins, the F-scores of predicted mutant interactions are 0.63 and 0.71, respectively. (D) Example of a matrix-based yeast two-hybrid screen. Yeast was spotted on medium lacking Leucine, Tryptophan, and Histidine, and supplemented with 1 mM 3-amino 1,2,4-triazole to suppress transcriptional autoactivation. Growth and hence interaction events, was scored after incubation at 20°C for 4 days.