Supplementary Figure 4: GA repeat and Telobox motifs are bound by class I BPC and C1-2iD Zn-finger TFs.

(a) Electrophoretic mobility shift assay to test association of BPC1 with the GA repeats or with mutated versions thereof. WT, M1 and M2 were also used as cold competitors. Class I BPC TFs are known to oligomerize^22,28,78. This, combined with the presence of two GA repeats in the tested DNA fragment, may explain why multiple shifted bands are observed when the protein is complexed with the DNA. Below: fraction of shifted DNA (% complex). Mean ± s.e.m. of three EMSA experiments. (b) Top: Diagram for motif-based yeast one hybrid screen. Bottom: The screen preferentially identified C2H2 ZnF proteins, in particular those of the C1-2iD subfamily (AZF1 and ZAT6) as Telobox (AAACCCTA) binding transcription factors. (c) Confirmation of Telobox interactome screen. Ten-fold serial dilutions of the yeast strains containing the bait DNA (b) integrated into the genome and plasmids containing C1-2iD Zn-finger TFs were plated on growth media (left) or on selection media (containing 600ng/ml aureobasidin A fungicide; right). See Supplementary Fig. 7 for a phylogenetic tree of ZnF TFs. The thin white line indicates where the plate image was cut.

78. Wanke, D. et al. Alanine zipper-like coiled-coil domains are necessary for homotypic dimerization of plant GAGA-factors in the nucleus and nucleolus. PLoS One 6, e16070 (2011)