| Type: | Domain | Name: | SAND domain |
| Description: | The SAND domain (named after Sp100, AIRE-1, NucP41/75, DEAF-1) is a conserved ~80 residue region found in a number of nuclear proteins, many of whichfunction in chromatin-dependent transcriptional control. These include proteins linked to various human diseases, such as the Sp100 (Speckled protein100 kDa), NUDR (Nuclear DEAF-1 related), GMEB (Glucocorticoid Modulatory Element Binding) proteins and AIRE-1 (Autoimmune regulator 1) proteins.Proteins containing the SAND domain have a modular structure; the SAND domain can be associated with a number of other modules, including the bromodomain, the PHD finger and the MYND finger.Because no SAND domain has been found in yeast, it is thought that the SAND domain could be restricted to animal phyla. Many SAND domain-containingproteins, including NUDR, DEAF-1 (Deformed epidermal autoregulatory factor-1) and GMEB, have been shown to bind DNA sequences specifically. The SAND domainhas been proposed to mediate the DNA binding activity of these proteins [, ].The resolution of the 3D structure of the SAND domain from Sp100b has revealed that it consists of a novel alpha/beta fold. The SAND domainadopts a compact fold consisting of a strongly twisted, five-stranded antiparallel beta-sheet with four alpha-helices packing against one side ofthe beta-sheet. The opposite side of the beta-sheet is solvent exposed. The beta-sheet and alpha-helical parts of the structure form two distinct regions.Multiple hydrophobic residues pack between these regions to form a structural core. A conserved KDWK sequence motif is found within the alpha-helical,positively charged surface patch. The DNA binding surface has been mapped to the alpha-helical region encompassing the KDWK motif []. | Short Name: | SAND_dom |
