 SHADOW CHROMO Domain | |
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Structure:
 The CSD/SC structure appears as a three-stranded antiparallel b-sheet followed by two a-helices. This closely resembles the chromodomain, but with two helices separated by a proline residue induced turn in place of the single a-helix of the chromodomain. Unlike the chromodomain, the CSD allows dimerization via interaction of the H2 helices. Dimerization of CSDs produces a hydrophobic pit capable of accommodating conserved hydrophobic pentapeptide motif (PXVXL) found in CSD interacting proteins. The figure shows the structure of the CSD of Swi6 as a monomer.
Structure Reference:
Cowieson, NP. et al. (2000) Curr. Biol. 10(9): 517-525. PDB: 1E0B.
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Domain binding and function:
 The Shadow Chromo Domain (CSD) is a 40 to 70 amino acid domain that occurs only in the context of proteins containing a chromodomain (CD). While the Shadow Chromodomain resembles the Chromodomain structurally, it appears to function in a distinct manner with respect to protein-protein interactions. The CSD lacks the hydrophobic sash believed to mediate CD interactions. Shadow Chromo domains form stable dimers and dimerization generates an interaction pit that may allow docking with partner proteins containing an extended hydrophobic pentapeptide motif.
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Examples of Proteins:
| SCD domain protein |
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Binding partner |
| Swi6 |  |
homotypic interaction |
| HP1 | |
Ku70, Su(var)3-7 |
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Referenced in part on Cell Signaling Technology Website, Reference Section on Protein Domains. We gratefully acknowledge the following contributors:
Piers Nash1, Dan Lin3, Kathleen Binns2, Clark Wells2, Rob Ingham2, Terry Kubiseski2, Bernard Liu1, Matt Smith2,3, Ivan Blasutig2,3, Maria Sierra1, Caesar Lim2,3, Michael Arc1, Jim Fawcett2 and Tony Pawson2,3.
1. Ben May Institute for Cancer Research, The University of Chicago, Chicago, Illinois, 60637, USA
2. Program in Molecular Biology and Cancer, Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, M5G 1X5, Canada
3. Department of Molecular and Medical Genetics, University of Toronto, Toronto, Ontario, M5S 1A8, Canada
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