Metal Ion Binding to Nucleic Acids

Abstract

Nucleic acids contain four different potential sites for binding of metal ions: the negatively charged phosphate oxygen atoms, the ribose hydroxyls, the base ring nitrogens, and the exocyclic base keto groups (Figure 8–1). Because metal ions like Mg(II), Ca(II), Na(I), and K(I) are present in the body in millimolar concentrations (Table 8–1), nucleic acids and nucleotides generally occur as complexes coordinated with metal ions. These complexes are of importance for the biological action of nucleic acids, nucleotides, coenzymes, and nucleoside di- and triphosphates and are the topic of this chapter.