Biology:SAND DNA-binding protein domain
| SAND | |||||||||
|---|---|---|---|---|---|---|---|---|---|
 Solution structure of the SAND domain of the putative nuclear protein homolog (5830484a20rik) | |||||||||
| Identifiers | |||||||||
| Symbol | SAND | ||||||||
| Pfam | PF01342 | ||||||||
| InterPro | IPR000770 | ||||||||
| SCOP2 | 1h5p / SCOPe / SUPFAM | ||||||||
| |||||||||
In molecular biology, the protein domain SAND is named after a range of proteins in the protein family: Sp100, AIRE-1, NucP41/75, DEAF-1. It is localised in the cell nucleus and has an important function in chromatin-dependent transcriptional control. It is found solely in eukaryotes.
Function
The precise function of the protein domain SAND remains to be determined. Nevertheless, it is thought to be a DNA binding domain despite its beta structure. This function can be inferred by studying the DEAF-1 transcription factor.[1] Here, the conserved positively charged residues in the SAND domains suggest the existence of negatively charged ligands. DNA is a negatively charged molecule due to the phosphate found in its backbone. Henceforth, this suggests that the SAND domain is the DNA-binding region of DEAF-1.[2]
Structure
The structure of this protein domain contains a globular fold. It is thought to have an alpha/beta secondary structure that consists of five beta strands.[2] This structure is made up of a five-stranded antiparallel beta-sheet with four alpha-helices. Further, the SAND domain is thought to have a modular structure; it can be associated with the bromodomain, the PHD finger and the MYND finger.[2]
Conservation
This protein domain has a conserved region of around 80 residues. Mutations in this region lead to various human diseases, particularly in these proteins: Sp100 (Speckled protein 100 kDa), NUDR (Nuclear DEAF-1 related), GMEB (Glucocorticoid Modulatory Element Binding) proteins and AIRE-1 (Autoimmune regulator 1) proteins.[2][3]
Some proteins with SAND domain
References
- ↑ "Finding the function buried in SAND.". Nat Struct Biol 8 (7): 568–70. 2001. doi:10.1038/89582. PMID 11427878.
- ↑ 2.0 2.1 2.2 2.3 "The SAND domain structure defines a novel DNA-binding fold in transcriptional regulation.". Nat Struct Biol 8 (7): 626–33. 2001. doi:10.1038/89675. PMID 11427895.
- ↑ "The APECED polyglandular autoimmune syndrome protein, AIRE-1, contains the SAND domain and is probably a transcription factor". Trends Biochem. Sci. 23 (7): 242–4. July 1998. doi:10.1016/s0968-0004(98)01231-6. PMID 9697411.
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