The ferric-uptake regulator (Fur) is an Fe2+-responsive transcription factor that coordinates iron homeostasis in many bacteria. Recently, we reported that expression of the Escherichia coli Fur regulon is also impacted by O2 tension. Here, we show that for most of the Fur regulon, Fur binding and transcriptional repression increase under anaerobic conditions, suggesting that Fur is controlled ...

Multiferroic behaviour at room temperature is demonstrated in ε-Fe2 O3 . The simple composition of this new ferromagnetic ferroelectric oxide and the discovery of a robust path for its thin film growth by using suitable seed layers may boost the exploitation of ε-Fe2 O3 in novel devices.

A pyridyl-functionalized diiron dithiolate complex, [μ-(4-pyCH2-NMI-S2)Fe2(CO)6] (3, py = pyridine (ligand), NMI = naphthalene monoimide) was synthesized and fully characterized. In the presence of zinc tetraphenylporphyrin (ZnTPP), a self-assembled 3·ZnTPP complex was readily formed in CH2Cl2 by the coordination of the pyridyl nitrogen to the porphyrin zinc center. Ultrafast photoinduced elect...

The electronic spin state of Fe2+ in ferropericlase, (Mg0.75Fe0.25)O, transitions from a high-spin (spin unpaired) to low-spin (spin paired) state within the Earth’s mid-lower mantle region. To better understand the local electronic environment of high-spin Fe2+ ions in ferropericlase near the transition, we obtained synchrotron Mössbauer spectra (SMS) of (Mg0.75,Fe0.25)O in externally heated a...

We present local density approximation augmented by the Hubbard-type correction calculations of high-temperature elastic properties of bridgmanite with composition (Mg(1−x)Fe x )SiO3 for 0≤×≤0.125. Results of elastic moduli and acoustic velocities for the Mg end-member (x=0) agree very well with the latest high-pressure and high-temperature experimental measurements. In the iron-bearing system,...

EDTA-derivatized deoxythymidine (dT-EDTA), incorporated into DNA and complexed to Fe2+ in the presence of dithiothreitol, is a widely used reagent for sequence-specific cleavage of duplex DNA. Using HPLC/electrospray mass spectrometry, we show that cleavage is specific to Fe2+, and no cleavage occurs when DNA-EDTA is complexed to other metal ions such as Ca2+, Mn2+, and Fe3+ even after many day...

A new bimetallic platform comprising a six-coordinate Fe(ONO)2 unit bound to an (ONO)M (M = Fe, Zn) has been discovered ((ONOcat)H3 = bis(3,5-di-tert-butyl-2-phenol)amine). Reaction of Fe(ONO)2 with either (ONOcat)Fe(py)3 or with (ONOq)FeCl2 under reducing conditions led to the formation of the bimetallic complex Fe2(ONO)3, which includes unique five- and six-coordinate iron centers. Similarly,...

This paper describes a comparative study of the decomposition of two nitrosyl iron complexes (NICs) with penicillamine thiolic ligands [Fe2(SC5H11NO2)2(NO)4]SO4 ·5H2O (I) and glutathione- (GSH-) ligands [Fe2(SC10H17N3O6)2(NO)4]SO4 ·2H2O (II), which spontaneously evolve to NO in aqueous medium. NO formation was measured by a sensor electrode and by spectrophotometric methods by measuring the for...

Janice L. Wong, Robert F. Higgins, Indrani Bhowmick, David Xi Cao, Géza Szigethy, Joseph W. Ziller, Matthew P. Shores* and Alan F. Heyduk* A new bimetallic platform comprising a six-coordinate Fe(ONO)2 unit bound to an (ONO)M (M1⁄4 Fe, Zn) has been discovered ((ONO)H3 1⁄4 bis(3,5-di-tert-butyl-2-phenol)amine). Reaction of Fe(ONO)2 with either (ONO)Fe(py)3 or with (ONO )FeCl2 under reducing cond...