| Description |
MADS-domain transcription factors are ubiquitously present in all plant and animals. In plant MADS-box genes are regulators of floral organ identity. It has a ~60 amino acid DNA-binding domains, and the protein is named after the first four describe members MADS domain (for MCM1, AG, DEF and SRF) and is present in all MADS-domain transcription factor. Structural analysis of animal and yeast MADS domains showed that the N-terminal and central parts of the MADS domain make contacts with the DNA, while the C-terminal part of this domain contributes mainly to protein dimerization, resulting in a DNA-binding protein dimer consisting of two interacting MADS monomers. The MADS-box gene family can be divided into two lineages, type I and type II, based on their protein domain structure. Genes from the type I have only the ~180 bp DNA sequence encoding the MADS domain. The type II lineage contains the well-studied floral homeotic genes. Plant type II MADS-domain proteins have a modular domain structure, which is referred to as the MIKC structure. They contain an N-terminally located DNA-binding MADS domain, followed by the I (intervening) and K (keratinlike) regions, which are essential for dimerization and higher-order complex formation, and finally a highly variable C-terminal domain, which may have roles in protein complex formation and transcriptional regulation.
Reference:
1. C. Smaczniak, R. G. Immink, G. C. Angenent, K. Kaufmann, Developmental and evolutionary diversity of plant MADS-domain factors: insights from recent studies. Development 139, 3081 (2012). |