Metal-binding biopolymers play a significant role in processes, such as regulation, recognition and catalysis, due to their high affinity towards specificmetal ions, which they bind selectively from the cellular pool. Many enzymes can bind two or more metal ions, each at a specific binding site, to enable efficient cooperative function. Imitating these recognition abilities might lead to the pr...

Human immunodeficiency virus (HIV) RNase H activity is essential for the synthesis of viral DNA by HIV reverse transcriptase (HIV-RT). RNA cleavage by RNase H requires the presence of divalent metal ions, but the role of metal ions in the mechanism of RNA cleavage has not been resolved. We measured HIV RNase H activity associated with HIV-RT protein in the presence of different concentrations o...

Due to the polyanionic nature of RNA, the principles of charge neutralization and electrostatic condensation require that cations help to overcome the repulsive forces in order for RNA to adopt a three-dimensional structure. A precise structural knowledge of RNA-metal ion interactions is crucial to understand the mechanism of metal ions in the catalytic or regulatory activity of RNA. We solved ...

Metal ions are inextricably associated with RNAs of any size and control their folding and activity to a large part. In order to understand RNA mechanisms, also the positioning, affinities and kinetics of metal ion binding must be known. Due to the spectroscopic silence and relatively fast exchange rates of the metal ions usually associated with RNAs, this task is extremely challenging and thus...

Metal ions play essential roles in about one third of enzymes [1]. These ions can modify electron flow in a substrate or enzyme, thus effectively controlling an enzyme-catalyzed reaction. They can serve to bind and orient substrate with respect to functional groups in the active site, and they can provide a site for redox activity if the metal has several valence states. Without the appropriate...

Metal ions are inextricably involved with nucleic acids due to their polyanionic nature. In order to understand the structure and function of RNAs and DNAs, one needs to have detailed pictures on the structural, thermodynamic, and kinetic properties of metal ion interactions with these biomacromolecules. In this review we first compile the physicochemical properties of metal ions found and used...

Marine microorganisms are presented with unique challenges to obtain essential metal ions required to survive and thrive in the ocean. The production of organic ligands to complex transition metal ions is one strategy to both facilitate uptake of specific metals, such as iron, and to mitigate the potential toxic effects of other metal ions, such as copper. A number of important trace metal ions...

A series of dinuclear complexes of a pseudocalixarene macrocycle H6L containing two 2,2'-methylenediphenol groups have been synthesised and structurally characterised. Using divalent metal ions, complexes containing a common hyperbolic paraboloid (saddle) M2(H4L)2+ core are formed. The structure is controlled by two strong O-H-O interactions resulting from metal ion-promoted monodeprotonation o...

Recently, Murray et al. (Chem Biol, 1998, 5:587-595) found that the hammerhead ribozyme does not require divalent metal ions for activity if incubated in high (> or =1 M) concentrations of monovalent ions. We further characterized the hammerhead cleavage reaction in the absence of divalent metal. The hammerhead is active in a wide range of monovalent ions, and the rate enhancement in 4 M Li+ is...