Differences in the C-termini of MADS-box proteins belonging to the STMADS16 subclade determine differences in their properties. The gaps were introduced to optimize the alignment of conserved residues. The prolines in the proline-rich domain are shown in bold and underlined. The acidic amino acids in the acidic domain are indicated in bold italics. The ability to self-activate in the 2-hybrid system was revealed by cell growth on SD/-Trp-His (1) and the expression of β-galactosidase, as determined by the development of a blue color in a nonlethal colony assay (2). Symbols + or –indicate growth or no growth (1) or the blue or white phenotype (2); nt is not tested. Homodimer formation (+) was detected as described in Results.