Zn(II) to Ag(I) Swap in Rad50 Zinc Hook Domain Leads to Interprotein Complex Disruption through the Formation of Highly Stable Ag(Cys) Cores.

The widespread application of silver nanoparticles in medicinal and daily life products increases the exposure to Ag(I) of thiol-rich biological environments, which help control the cellular metallome. A displacement of native metal cofactors from their cognate protein sites is a known phenomenon for carcinogenic and otherwise toxic metal ions. Here, we examined the interaction of Ag(I) with the peptide model of the interprotein zinc hook (Hk) domain of Rad50 protein from , a key player in DNA double-strand break (DSB) repair.

An Extremely Stable Interprotein Tetrahedral Hg(Cys) Core Forms in the Zinc Hook Domain of Rad50 Protein at Physiological pH.

Invited for the cover of this issue is the group of Artur Krężel at the University of Wrocław in collaboration with Lars Hemmingsen at The University of Copenhagen and Eva Freisinger at the University of Zürich. The image depicts the outcomes of Hg interactions with Rad50 protein. Read the full text of the article at 10.

An Extremely Stable Interprotein Tetrahedral Hg(Cys) Core Forms in the Zinc Hook Domain of Rad50 Protein at Physiological pH.

In nature, thiolate-based systems are the primary targets of divalent mercury (Hg ) toxicity. The formation of Hg(Cys) cores in catalytic and structural protein centers mediates mercury's toxic effects and ultimately leads to cellular damage. Multiple studies have revealed distinct Hg -thiolate coordination preferences, among which linear Hg complexes are the most commonly observed in solution at physiological pH.

Metal Exchange in the Interprotein Zn -Binding Site of the Rad50 Hook Domain: Structural Insights into Cd -Induced DNA-Repair Inhibition.

Cd is a major genotoxic agent that readily displaces Zn in a multitude of zinc proteins, abrogates redox homeostasis, and deregulates cellular metalloproteome. To date, this displacement has been described mostly for cysteine(Cys)-rich intraprotein binding sites in certain zinc finger domains and metallothioneins. To visualize how a Zn -to-Cd swap can affect the target protein's status and thus understand the molecular basis of Cd -induced genotoxicity an intermolecular Zn -binding site from the crucial DNA repair protein Rad50 and its zinc hook domain were examined.

Structural zinc binding sites shaped for greater works: Structure-function relations in classical zinc finger, hook and clasp domains.

Metal ions are essential elements present in biological systems able to facilitate many cellular processes including proliferation, signaling, DNA synthesis and repair. Zinc ion (Zn(II)) is an important cofactor for numerous biochemical reactions. Commonly, structural zinc sites demonstrate high Zn(II) affinity and compact architecture required for sequence-specific macromolecule binding.

Interaction of 2',3'-cAMP with Rbp47b Plays a Role in Stress Granule Formation.

2',3'-cAMP is an intriguing small molecule that is conserved among different kingdoms. 2',3'-cAMP is presumably produced during RNA degradation, with increased cellular levels observed especially under stress conditions. Previously, we observed the presence of 2',3'-cAMP in Arabidopsis () protein complexes isolated from native lysate, suggesting that 2',3'-cAMP has potential protein partners in plants.