DM domain

In molecular biology the DM domain is a protein domain first discovered in the doublesex proteins of Drosophila melanogaster and is also seen in proteins from Caenorhabditis elegans. In D. melanogaster the doublesex gene controls somatic sexual differentiation by producing alternatively spliced mRNAs encoding related sex-specific polypeptides. These proteins are believed to function as transcription factors on downstream sex-determination genes, especially on neuroblast differentiation and yolk protein genes transcription. The DM domain binds DNA as a dimer, allowing the recognition of pseudopalindromic sequences. The NMR analysis of the DSX DM domain revealed a novel zinc module containing 'intertwined' CCHC and HCCC zinc-binding sites. The recognition of the DNA requires the carboxy-terminal basic tail which contacts the minor groove of the target sequence.