Water and monovalent ions in the minor groove of B-DNA oligonucleotides as seen by NMR

During the past 8 years, two complementary nmr techniques—magnetic relaxation dispersion and nuclear Overhauser effect spectroscopy—have been applied extensively to the study of water and monovalent ions in the minor groove of B-DNA oligonucleotides in solution. In this review, the possibilities and limitations of the two methods are outlined, with emphasis on the interpretational steps whereby molecular-level information is extracted from the primary data. The results on sequence-dependent hydration and ion–DNA interactions obtained so far by these methods is summarized and critically assessed. The nmr results are also compared with structural data from x-ray crystallography.