Solution Structure of the Arabidopsis thaliana Telomeric Repeat-binding Protein DNA Binding Domain: A New Fold with an Additional C-terminal Helix
| Autor: | Ben C. Chung, Tai Huang Huang, Shih Che Sue, Chia Hsing Ho, Ying Hsien Cheng, Hsin Hao Hsiao, Chung Mong Chen, Kuang Lung Hsueh |
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| Rok vydání: | 2006 |
| Předmět: |
Models
Molecular Protein Folding DNA Plant HMG-box Stereochemistry Molecular Sequence Data Arabidopsis Sequence alignment Biology Protein Structure Secondary chemistry.chemical_compound Protein structure Structural Biology Animals Humans Amino Acid Sequence Telomeric Repeat Binding Protein 1 Nuclear Magnetic Resonance Biomolecular Molecular Biology Peptide sequence Sequence Homology Amino Acid DNA-binding domain Molecular biology Protein Structure Tertiary DNA binding site chemistry Hydrophobic and Hydrophilic Interactions Sequence Alignment DNA Protein Binding Binding domain |
| Zdroj: | Journal of Molecular Biology. 356:72-85 |
| ISSN: | 0022-2836 |
| DOI: | 10.1016/j.jmb.2005.11.009 |
| Popis: | The double-stranded telomeric repeat-binding protein (TRP) AtTRP1 is isolated from Arabidopsis thaliana. Using gel retardation assays, we defined the C-terminal 97 amino acid residues, Gln464 to Val560 (AtTRP1(464-560)), as the minimal structured telomeric repeat-binding domain. This region contains a typical Myb DNA-binding motif and a C-terminal extension of 40 amino acid residues. The monomeric AtTRP1(464-560) binds to a 13-mer DNA duplex containing a single repeat of an A.thaliana telomeric DNA sequence (GGTTTAG) in a 1:1 complex, with a K(D) approximately 10(-6)-10(-7) M. Nuclear magnetic resonance (NMR) examination revealed that the solution structure of AtTRP1(464-560) is a novel four-helix tetrahedron rather than the three-helix bundle structure found in typical Myb motifs and other TRPs. Binding of the 13-mer DNA duplex to AtTRP1(464-560) induced significant chemical shift perturbations of protein amide resonances, which suggests that helix 3 (H3) and the flexible loop connecting H3 and H4 are essential for telomeric DNA sequence recognition. Furthermore, similar to that in hTRF1, the N-terminal arm likely contributes to or stabilizes DNA binding. Sequence comparisons suggested that the four-helix structure and the involvement of the loop residues in DNA binding may be features unique to plant TRPs. |
| Databáze: | OpenAIRE |
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