| Primary Identifier | IPR033897 | Type | Domain |
| Short Name | MADS_SRF-like |
| description | SRF-like/Type I subfamily of MADS (MCM1, Agamous, Deficiens, and SRF (serum response factor)) box family of eukaryotic transcriptional regulators []. Binds DNA and exists as hetero- and homo-dimers [, ]. Differs from the MEF-like/Type II subgroup mainly in position of the alpha 2 helix responsible for the dimerization interface. Important in homeotic regulation in plants and in immediate-early development in animals []. Also found in fungi [, ].Human serum response factor (SRF) is a ubiquitous nuclear protein important for cell proliferation and differentiation. SRF function is essential for transcriptional regulation of numerous growth-factor-inducible genes, such as c-fos oncogene and muscle-specific actin genes. A core domain of around 90 amino acids is sufficient for the activities of DNA-binding, dimerisation and interaction with accessory factors. Within the core is a DNA-binding region, designated the MADS box [], that is highly similar to many eukaryotic regulatory proteins: among these are MCM1, the regulator of cell type-specific genes in fission yeast; DSRF, a Drosophila trachea development factor; the MEF2 family of myocyte-specific enhancer factors; and the Agamous and Deficiens families of plant homeotic proteins.In SRF, the MADS box has been shown to be involved in DNA-binding and dimerisation []. Proteins belonging to the MADS family function as dimers, the primary DNA-binding element of which is an anti-parallel coiled coil of two amphipathic α-helices, one from each subunit. The DNA wraps around the coiled coil allowing the basic N-termini of the helices to fit into the DNA major groove. The chain extending from the helix N-termini reaches over the DNA backbone and penetrates into the minor groove. A 4-stranded, anti-parallel β-sheet packs against the coiled-coil face opposite the DNA and is the central element of the dimerisation interface. The MADS-box domain is commonly found associated with K-box region see (). |
