Most eukaryotes contain iron-sulfur cluster (ISC) assembly proteins related to Saccharomyces cerevisiae Isa1 and Isa2. We show here that Isa1 but not Isa2 can be functionally replaced by the bacterial relatives IscA, SufA, and ErpA. The specific function of these "A-type" ISC proteins within the framework of mitochondrial and bacterial Fe/S protein biogenesis is still unresolved. In a comprehen...

Conservation of energy based on the reduction of sulfate is of fundamental importance for the biogeochemical sulfur cycle. A key enzyme of this ancient anaerobic process is the dissimilatory sulfite reductase (dSir), which catalyzes the six-electron reduction of sulfite to hydrogen sulfide under participation of a unique magnetically coupled siroheme-[4Fe-4S] center. We determined the crystal s...

Biotin synthase is an iron-sulfur protein that utilizes AdoMet to catalyze the presumed radical-mediated insertion of a sulfur atom between the saturated C6 and C9 carbons of dethiobiotin. Biotin synthase (BioB) is aerobically purified as a dimer that contains [2Fe-2S](2+) clusters and is inactive in the absence of additional iron and reductants, and anaerobic reduction of BioB with sodium dith...

A number of SO3H-functionalized solids (biochar, montmorillonites, carbon and halloysite nanotubes) has been studied as catalysts in the cascade Prins-Ritter reaction (-)-isopulegol with benzaldehyde acetonitrile for synthesis octahydro-2H-chromene amides (as 4R- 4S-isomers). high selectivity to these products at 30 °C presence H2O was observed on modified chlorosulfonic acid (CSA) reaching 84%...

Radiofrequency ablation (RFA) of atrial fibrillation (AF) using high-power short-duration (HPSD) settings (50W, 10s or up to 90W, 4s) are increasingly common, seeking maximize resistive rather than conductive heating limit the risk esophageal damage. The real-time luminal temperature (LET) response and damage HPSD not fully established. To investigate LET RFA on posterior LA wall. We ablated de...

A fundamental challenge in the redox biology of Mycobacterium tuberculosis (Mtb) is to understand the mechanisms involved in sensing redox signals such as oxygen (O2), nitric oxide (NO), and nutrient depletion, which are thought to play a crucial role in persistence. Here we show that Mtb WhiB3 responds to the dormancy signals NO and O2 through its iron-sulfur (Fe-S) cluster. To functionally as...

The formal synthesis of (+)-3-epi-eupomatilone-6 () and the 3,5-bis-epimer () has been accomplished. The key synthetic strategy involved the stereoselective construction of (3R,4S,5R)- and (3R,4S,5S)-trisubstituted γ-butyrolactones and from (2R,3R)-2,3-dimethyl-4-pentenoic acid derivative , which was readily obtained via stereoselective conjugate addition of vinylmagnesium chloride to a chiral ...

A pair of B 0 ¯ B 0 mesons from Υ(4S) decay exhibit EPR type non-local particle-antiparticle (flavor) correlation. It is possible to write down Bell Inequality (in the CHSH form: S ≤ 2) to test the non-locality assumption of EPR. Using semileptonic B 0 decays of Υ(4S) at Belle experiment, a clear violation of Bell Inequality in particle-antiparticle correlation is observed: S = 2.725 ± 0.167sta...

Based on a data sample of 81.7 fb collected at the Υ(4S) resonance with the BaBar detector at the PEP-II asymmetric-energy B Factory at SLAC, we present the current status of the measurement of the branching fraction of Υ(4S) → BB̄. Our study of the decay was performed through the exclusive decays B̄ → D∗+l−ν̄l using a partial reconstruction method, where the D ∗+ is detected only through the soft...

The EPR spectrum of the reduced Fe-protein from nitrogenase has been reinvestigated. The dependences on temperature, microwave power, and microwave frequency all suggest that the observed signal represents a magnetically isolated [4Fe-4S]1+(2+;1+) cluster. Also, the signal can be simulated assuming a simple, g-strained S = 1/2 system. However, the integrated intensity amounts to no more than 0....