Divalent metal ions are required virtually in every stage of genetic information transfer, and have profound effects on the structures and functions of nucleic acids. This article reviews the current developments of X-ray diffraction studies of metal ion interactions with nucleic acid constituents. The following important findings and topics are briefly presented ; metal binding sites, metal binding effects on the structural dimensions and conformations of nucleic acid constituents, molecular structures of metalnucleotide complexes, metal binding mode in ternary metal ion-nucleotide complexes containing aromatic heterocyclic ligands, which have been studied as a simple model for nucleic acid-metalion-enzyme system, and binding modes of anti-tumor agents, cisammine platinum (II) complexes with nucleic acids.
