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Sequential NMR assignments of labile protons in DNA using two-dimensional nuclear-Overhauser-enhancemnt spectroscopy with three jump-and-return pulse sequences

1987; Wiley; Volume: 166; Issue: 1 Linguagem: Inglês

10.1111/j.1432-1033.1987.tb13504.x

1432-1033

Gottfried Otting, Rolf GRUTTER, Werner Leupin, Kurt Wüthrich, Carlo Minganti, K. N. Ganesh, Brian S. Sproat, Michael J. Gait,

Spectroscopy and Quantum Chemical Studies

Two-dimensional nuclear Overhauser enhancement (NOESY) spectra of labile protons were recorded in H2O solutions of a protein and of a DNA duplex, using a modification of the standard NOESY experiment with all three 90° pulses replaced by jump-and-return sequences. For the protein as well as the DNA fragment the strategically important spectral regions could be recorded with good sensitivity and free of artifacts. Using this procedure, sequence-specific assignments were obtained for the imino protons, C2H of adenine, and C4NH2 of cytosine in a 23-base-pair DNA duplex which includes the 17-base-pair OR3 repressor binding site of bacteriophage λ. Based on comparison with previously published results on the isolated OR3 binding site, these data were used for a study of chain termination effects on the chemical shifts of imino proton resonances of DNA duplexes.