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NMR and Structural Studies of Telomere Binding Protein, CEH-37 from Caenorhabditis elegans. Sunjin Moon Structural Biochemistry & Molecular Biophysics Lab. Department of Biochemistry, College of Life Science and Biotechnology Yonsei University, Seoul, 120-740, Korea.
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NMR and Structural Studies of Telomere Binding Protein, CEH-37 from Caenorhabditis elegans Sunjin Moon Structural Biochemistry & Molecular Biophysics Lab. Department of Biochemistry, College of Life Science and Biotechnology Yonsei University, Seoul, 120-740, Korea
C. elegance Telomere binding protein • • Identification of CEH-37 • as the nematode telomere binding protein. • CEH-37 specifically binds to C. elegans • telomere sequence in vitro. • The nematode telomeric DNA consists • of TTAGGC repeats, a sequence • motif differs from that of mammals and plants. • • C.elegance teromeric DNA have a repeatable • sequences (TTAGGC)1.5and the minimun • DNA length which interact with telomere • proteins is 9-mer. Structural Biochemistry & Molecular Biophysics Lab.
Protein Purification B. B. Size exclusion analysis for recognizing native CEH-37 state. Structural Biochemistry & Molecular Biophysics Lab.
C-term α3 α1 N-term α2 Secondary structure analysis and homology modeling A. C. B. • Secondary structure analysis using TALOS • B. Secondary structure of CEH-37 • C. Tertiary structure of CEH-37 ; helix-loop-helix Structural Biochemistry & Molecular Biophysics Lab.
The side-chain analysis of CEH-37 (28-95) A. B. C. D. • HCCH-TOCSY B. 13C-NOESY C. HBHACONH D.15N-HSQC Structural Biochemistry & Molecular Biophysics Lab.
NMR titration of 15N labeled CEH-37 and telomere DNA A. B. Molar ratio Red , DNA:Protein = 1:1 Yellow, DNA:Protein = 0.5:1 Green, DNA:Protein = 0.2 :1 • NMR titration B. Chemical shift change Structural Biochemistry & Molecular Biophysics Lab.
Surface charge model of CEH-37 Helix α-3 has positive charged amino acids, which might take part in DNA-protein interaction Structural Biochemistry & Molecular Biophysics Lab.
NMR assignment A. B. • 1H-15N HSQC spectrum and Backbone assignment of CEH-37 Free state. • 1H-15N HSQC spectrum and Backbone assignment of CEH-37& C.elegance DNA Complex. Structural Biochemistry & Molecular Biophysics Lab.
Helix 1 Helix 3 W52 Q50 R7 T10 Chemical shift Change (ᅀδ) E8 R48 0.4 Residue Numbers NMR Characterization B. A. A.NMR Characterization of CEH-37 & C.elegance DNA Complex B. DNA-protein interaction region Structural Biochemistry & Molecular Biophysics Lab.
Discussion 1.The three-dimensional model of the homeodomain of CEH-37, which has a typical helix-loop-helix structure, was similar to that of the Myb domain of known telomere-binding proteins, which is also a helix-loop-helix protein, despite little amino acid sequence similarity. 2. We showed result of the c.elegance DNA bindin protein, CEH-37 that were uniguely bind to only c.elegance DNA using the isothermal titration calorimetry (ITC). CEH-3 bound to c.elegance telomere repeats (TTAGGC)1.5. 3. We demonstrated that the DNA binding domain of CEH-37 get structure change by interecting with c.elegance DNA. Structural Biochemistry & Molecular Biophysics Lab.
Acknowledgement Yonsei University Prof. Weontae Lee Dr. Sunggeon Ko Ph.D. Jihye Yoon M.S. Youngmin Lee