Temperature-Induced Replacement of Phosphate Proton with Metal Ion Captured in Neutron Structures of A-DNA (Structure)

Vandavasi et al. used joint X-ray/neutron macromolecular crystallography to follow structural changes in an A-DNA oligonucleotide induced by temperature. The study visualized hydrogen atom positions, revealing protonation of a backbone phosphate oxygen at room temperature and the proton replacement with hydrated magnesium ion upon cooling the crystal to 100 K.