The DNA structure responds differently to physiological concentrations of K(+) or Na(+).
The influence of monovalent cations on DNA conformation and readout is an open question. This NMR study of DNA with either Na(+) or K(+) at physiological concentrations shows that the nature of the cation affects the (31)P chemical shifts (deltaP) and the sequential distances H2'(i)-H6/8(i+1), H2"(i)-H6/8(i+1), and H6/8(i)-H6/8(i+1). The deltaP and distance variations ascertain that the nature of the cation affects the DNA overall structure, i.e. both the conformational equilibria between the backbone BI (epsilon-zeta <0 degrees ) and BII (epsilon-zeta >0 degrees ) states and the helical parameters, via their strong mechanical coupling. These results reveal that Na(+) and K(+) interactions with DNA are different and sequence-dependent. These ions modulate the overall intrinsic properties of DNA, and possibly its packaging and readout.
Heddi
Brahim
B
Laboratoire de Biochimie Théorique, CNRS UPR 9080, Institut de Biologie Physico-chimique, 13 rue Pierre et Marie Curie, Paris 75005, France.
Foloppe
Nicolas
N
Hantz
Edith
E
Hartmann
Brigitte
B
D002021:Buffers; D018360:Crystallography, X-Ray; D004247:DNA / Q000737:chemistry*; D008969:Molecular Sequence Data; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D009690:Nucleic Acid Conformation; D009841:Oligonucleotides / Q000737:chemistry / Q000235:genetics; D011188:Potassium / Q000737:chemistry*; D016760:Proto-Oncogene Proteins c-fos / Q000737:chemistry / Q000235:genetics; D016755:Proto-Oncogene Proteins c-jun / Q000737:chemistry / Q000235:genetics; D012964:Sodium / Q000737:chemistry*
D002021:Buffers; D009841:Oligonucleotides; D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun; D004247:DNA; D012964:Sodium; D011188:Potassium