Complete assignment of signals in 1D and 2D H-NMR spectra of a 17-member oligonucleotide, a model symmetrical analog of lambda operators

A synthetic analog of lambda phage operators, a symmetric duplex of oligonucleotides, was studied by 1H NMR at 400 MHz. Signals in the spectrum of imino protons of the duplex in H2O were assigned based on the results of NOE experiments and temperature dependences. Resonance assignment of the non-exchangeable protons of bases and deoxyribose was performed by analysing the NOESY spectrum obtained in the single experiment. The results indicate that the major part of the duplex has a conformation similar to the B-form of DNA, and the region of the central non-complementary base pair exhibits deviations from the regular structure.