Identification of distinct SET/TAF-Ibeta domains required for core histone binding and quantitative characterisation of the interaction
| Autor: | Karetsou, Z., Emmanouilidou, A., Sanidas, I., Liokatis, S., Nikolakaki, E., Politou, A. S., Papamarcaki, T. |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2009 |
| Předmět: |
Recombinant Proteins/metabolism
Histones/*metabolism Molecular Chaperones/metabolism Circular Dichroism Molecular Sequence Data Transcription Factors/chemistry/*metabolism Protein Structure Tertiary Chromatin/metabolism Mutant Proteins/metabolism Spectrometry Fluorescence Histone Chaperones Amino Acid Sequence Chromosomal Proteins Non-Histone/chemistry/*metabolism Protein Binding |
| Popis: | BACKGROUND: The assembly of nucleosomes to higher-order chromatin structures is finely tuned by the relative affinities of histones for chaperones and nucleosomal binding sites. The myeloid leukaemia protein SET/TAF-Ibeta belongs to the NAP1 family of histone chaperones and participates in several chromatin-based mechanisms, such as chromatin assembly, nucleosome reorganisation and transcriptional activation. To better understand the histone chaperone function of SET/TAF-Ibeta, we designed several SET/TAF-Ibeta truncations, examined their structural integrity by circular Dichroism and assessed qualitatively and quantitatively the histone binding properties of wild-type protein and mutant forms using GST-pull down experiments and fluorescence spectroscopy-based binding assays. RESULTS: Wild type SET/TAF-Ibeta binds to histones H2B and H3 with Kd values of 2.87 and 0.15 microM, respectively. The preferential binding of SET/TAF-Ibeta to histone H3 is mediated by its central region and the globular part of H3. On the contrary, the acidic C-terminal tail and the amino-terminal dimerisation domain of SET/TAF-Ibeta, as well as the H3 amino-terminal tail, are dispensable for this interaction. CONCLUSION: This type of analysis allowed us to assess the relative affinities of SET/TAF-Ibeta for different histones and identify the domains of the protein required for effective histone recognition. Our findings are consistent with recent structural studies of SET/TAF-Ibeta and can be valuable to understand the role of SET/TAF-Ibeta in chromatin function. BMC Biochem |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|