The 2D {31P} Spin-Echo-Difference Constant-Time [13C, 1H]-HMQC Experiment for Simultaneous Determination of 3JH3′P and 3JC4′P in 13C-Labeled Nucleic Acids and Their Protein Complexes
✍ Scribed by Thomas Szyperski; César Fernández; Akira Ono; Kurt Wüthrich; Masatsune Kainosho
- Publisher
- Elsevier Science
- Year
- 1999
- Tongue
- English
- Weight
- 163 KB
- Volume
- 140
- Category
- Article
- ISSN
- 1090-7807
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✦ Synopsis
A two-dimensional { 31 P} spin-echo-difference constant-time [ 13 C, 1 H]-HMQC experiment (2D { 31 P}-sedct-[ 13 C, 1 H]-HMQC) is introduced for measurements of 3 J C4P and 3 J H3P scalar couplings in large 13 C-labeled nucleic acids and in DNA-protein complexes. This experiment makes use of the fact that 1 H-13 C multiplequantum coherences in macromolecules relax more slowly than the corresponding 13 C single-quantum coherences. 3 J C4P and 3 J H3P are related via Karplus-type functions with the phosphodiester torsion angles  and ⑀, respectively, and their experimental assessment therefore contributes to further improved quality of NMR solution structures. Data are presented for a uniformly 13 C, 15 N-labeled 14-base-pair DNA duplex, both free in solution and in a 17-kDa protein-DNA complex.