1. Structure of the Coiled-Coil Dimerization Motif of Sir4 and Its Interaction with Sir3
- Author
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Ju Fang Chang, Jason C. Tanny, Danesh Moazed, David J. Filman, Brian E. Hall, and Tom Ellenberger
- Subjects
Models, Molecular ,Protein Denaturation ,Protein Conformation ,Molecular Sequence Data ,Saccharomyces cerevisiae ,Crystallography, X-Ray ,Histone Deacetylases ,03 medical and health sciences ,Motif (narrative) ,0302 clinical medicine ,Protein structure ,Sirtuin 2 ,Structural Biology ,Gene Expression Regulation, Fungal ,Histone code ,Sirtuins ,Amino Acid Sequence ,Ternary complex ,Molecular Biology ,ChIA-PET ,Silent Information Regulator Proteins, Saccharomyces cerevisiae ,030304 developmental biology ,Physics ,Coiled coil ,Genetics ,0303 health sciences ,biology ,Circular Dichroism ,Chromatin ,Molecular Weight ,Crystallography ,enzymes and coenzymes (carbohydrates) ,Histone ,biology.protein ,Biophysics ,Histone deacetylase ,Dimerization ,Sequence Alignment ,030217 neurology & neurosurgery - Abstract
The yeast silent information regulators Sir2, Sir3, and Sir4 physically interact with one another to establish a transcriptionally silent state by forming repressive chromatin structures. The Sir4 protein contains binding sites for both Sir2 and Sir3, and these protein-protein interactions are required for gene silencing. Here, we report the X-ray structure of the coiled-coil dimerization motif within the C-terminus of Sir4 and show that it forms a stable 1:1 complex with a dimeric fragment of Sir3 (residues 464–978). We have identified a cluster of residues on the surface of the Sir4 coiled coil required for specific interactions with Sir3. The histone deacetylase Sir2 can also bind to this complex, forming a ternary complex with the truncated Sir3 and Sir4 proteins. The dual interactions of Sir4 with Sir3 and Sir2 suggest a physical basis for recruiting Sir3 to chromatin by virtue of its interactions with Sir4 and with deacetylated histones in chromatin. more...
- Published
- 2004
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