Fig. 2: Type I MADS possesses I domain-like region which is required for both dimerisation and DNA binding.

a Amino acid enrichment of the I region (~30 amino acids C-terminal to the M domain) of type I, type II and all MADS TFs, logos generated with WebLogo⁷⁷. The overall height of the stack in each position indicates the sequence information content at that position, while the height of the amino acid symbols within the stack indicates the relative frequency at each position. The MADS TF sequences are taken from The Arabidopsis Information Resource (www.arabidopsis.org). b, c Pull-down assay showing that M domain of AGL61 (AGL61^M) does not interact with the M domain of PHE (PHE^M) or AGL80 (AGL80^M). d, e Pull-down assay showing that the M domain plus the I-like region of AGL61 (AGL61^MI) interacts with the MI region of PHE (PHE^MI) and AGL80 (AGL80^MI). All assays were performed twice and a representative blot is shown. f EMSA assay showing that heterodimers AGL61^MI-AGL80^MI and AGL61^MI-PHE^MI shift a DNA sequence containing a canonical CArG-box binding site from the SEP3 promoter, while their corresponding constructs without the I region do not exhibit any binding. All EMSAs were performed at least twice and a representative gel is shown.