RNA tumor viruses contain a characteristic RNA-dependent DNA polymerase (reverse transcriptase) which has been thought to be related to the induction of leukemia by this virus. A disturbance in a zinc-dependent enzyme system was first postulated to account for the demonstrated differences in zinc metabolism of normal and leukemic leukocytes [Vallee et al. in (1949) Acta Unio. Int. Contra Cancru...

Catalases (CAT) are antioxidant metalloenzymes necessary for life in oxygen-metabolizing cells to regulate H2O2 concentration by accelerating its dismutation. Many physiopathological situations associated with oxidative stress resulting from overproduction, during which defenses overwhelmed. We have used a combinatorial approach an activity-based screening discover first peptidyl di-copper comp...

Constraining the timing of eukaryogenesis and divergence eukaryotic clades is a major challenge in evolutionary biology. Here, we present trace metal concentration zinc isotope data for c. 2.1 billion-year-old Francevillian Group pyritized structures, previously described as putative remnants first colonial multicellular organisms, their host black shales. Relative to rocks, structures are stro...

Thiocyanate hydrolase (TCH) is a pink bacterial metalloenzyme found in Thiobacillus thioparus THI 115 that catalyzes the conversion of thiocyanate to carbonyl sulfide and ammonia.1,2 Although TCH has not been well characterized spectroscopically, an analysis of the genes encoding for the enzyme has shown a high active-site sequence homology to the metalloenzyme nitrile hydratase (NHase), includ...

Hydrogenasen sind H2-umsetzende Metalloenzyme und enthalten katalytische Kofaktoren, deren Eisenionen durch biologisch ungewöhnliche Kohlenmonoxid- (CO) Cyanid- (CN−) Liganden koordiniert sind. Externes CO CN−hemmt jedoch. Der molekulare Mechanismus der Bindung von CN− an [FeFe]-Hydrogenasen ist unbekannt. In dieser Studie präsentieren wir Kristallstrukturen mit behandelten [FeFe]-Hydrogenase C...

The hammerhead ribozyme is generally accepted as a well characterized metalloenzyme. However, the precise nature of the interactions of the RNA with metal ions remains to be fully defined. Examination of metal ion-catalyzed hammerhead reactions at limited concentrations of metal ions is useful for evaluation of the role of metal ions, as demonstrated in this study. At concentrations of Mn2+ ion...

RNase P is the ubiquitous ribonucleoprotein metalloenzyme responsible for cleaving the 5'-leader sequence of precursor tRNAs during their maturation. While the RNA subunit is catalytically active on its own at high monovalent and divalent ion concentrations, four protein subunits are associated with archaeal RNase P activity in vivo: RPP21, RPP29, RPP30, and POP5. These proteins have been shown...