A number of transcription factors contain a conserved domain of 56 amino-acid residues, sometimes known as the MADS-box domain. They are listed below:

• Serum response factor (SRF) [1], a mammalian transcription factor that binds to the Serum Response Element (SRE). This is a short sequence of dyad symmetry located 300 bp to the 5' end of the transcription initiation site of genes such as c-fos.
• Mammalian myocyte-specific enhancer factors 2A to 2D (MEF2A to MEF2D). These proteins are transcription factor which binds specifically to the MEF2 element present in the regulatory regions of many muscle-specific genes.
• Drosophila myocyte-specific enhancer factor 2 (MEF2).
• Yeast GRM/PRTF protein (gene MCM1) [2], a transcriptional regulator of mating-type-specific genes.
• Yeast arginine metabolism regulation protein I (gene ARGR1 or ARG80).
• Yeast transcription factor RLM1.
• Yeast transcription factor SMP1.
• Arabidopsis thaliana agamous protein (AG) [3], a probable transcription factor involved in regulating genes that determines stamen and carpel development in wild-type flowers. Mutations in the AG gene result in the replacement of the stamens by petals and the carpels by a new flower.
• Arabidopsis thaliana homeotic proteins Apetala1 (AP1), Apetala3 (AP3) and Pistillata (PI) which act locally to specify the identity of the floral meristem and to determine sepal and petal development [4].
• Antirrhinum majus and tobacco homeotic protein deficiens (DEFA) and globosa (GLO) [5]. Both proteins are transcription factors involved in the genetic control of flower development. Mutations in DEFA or GLO cause the transformation of petals into sepals and of stamina into carpels.
• Arabidopsis thaliana putative transcription factors AGL1 to AGL6 [6].
• Antirrhinum majus morphogenetic protein DEF H33 (squamosa).

In SRF, the conserved domain has been shown [1] to be involved in DNA-binding and dimerization. We have derived a pattern that spans the complete length of the domain. The profile also spans the length of the MADS-box.