The hammerhead ribozyme crystal structure identified a specific metal ion binding site referred to as the P9/G10.1 site. Although this metal ion binding site is approximately 20 A away from the cleavage site, its disruption is highly deleterious for catalysis. Additional published results have suggested that the pro-R(P) oxygen at the cleavage site is coordinated by a metal ion in the reaction'...

PP2C family phosphatases (the type 2C family of protein phosphatases; or metal-dependent phosphatase, PPM) constitute an important class of signaling enzymes that regulate many fundamental life activities. All PP2C family members have a conserved binuclear metal ion active center that is essential for their catalysis. However, the catalytic role of each metal ion during catalysis remains elusiv...

Previously metal-ion sites have been used as structural and functional probes in seven transmembrane receptors (7TM), but as yet all the engineered sites have been inactivating. Based on presumed agonist interaction points in transmembrane III (TM-III) and -VII of the beta(2)-adrenergic receptor, in this paper we construct an activating metal-ion site between the amine-binding Asp-113 in TM-III...

One of the first kinetic studies of metal ion reorganisation between the different sites of a tritopic polyaza ligand reveals well defined pathways for the movement of the metal ion.

Transition metals are essential for many metabolic processes, and their homeostasis is crucial for life. Metal-ion transporters play a major role in maintaining the correct concentrations of the various metal ions in living cells. Little is known about the transport mechanism of metal ions by eukaryotic cells. Some insight has been gained from studies of the mammalian transporter DCT1 and the y...

The first component of human complement (C1) was reconstituted from equimolar concentrations of its purified subunits C1q, C1r, and C1s, in the presence of each of nine different metal ions for the purpose of studying the qualitative and quantitative nature of the metal ion requirement for C1 assembly and function. For C1 reconstituted with each metal ion, three assays characteristic of C1 were...

The presence of catalytic metal ions in RNA active sites has often been inferred from metal-ion rescue of modified substrates and sometimes from inhibitory effects of alternative metal ions. Herein we report that, in the Tetrahymena group I ribozyme reaction, the deleterious effect of a thio substitution at the pro-Sp position of the reactive phosphoryl group is rescued by Mn2+. However, analys...

Designed metal ion binding peptides offer a variety of applications in both basic science as model systems of more complex metalloproteins, and in biotechnology, e.g. in bioremediation of toxic metal ions, biomining or as artificial enzymes. In this work a peptide (HS: Ac-SCHGDQGSDCSI-NH2) has been specifically designed for binding of both Zn(II) and Hg(II), i.e. metal ions with different prefe...