Spectroscopic evidence for an all-ferrous [4Fe–4S]0 cluster in the superreduced activator of 2-hydroxyglutaryl-CoA dehydratase from Acidaminococcus fermentans

The key enzyme of the fermentation of glutamate by Acidaminococcus fermentans, 2-hydroxyglutarylcoenzyme A dehydratase, catalyzes the reversible syn-elimination of water from (R)-2-hydroxyglutaryl-coenzyme A, resulting in (E)-glutaconylcoenzyme A. The dehydratase system consists of two oxygen-sensitive protein components, the activator (HgdC) and the actual dehydratase (HgdAB). Previous biochemical and spectroscopic studies revealed that the reduced [4Fe–4S]+ cluster containing activator transfers one electron to the dehydratase driven by ATP hydrolysis, which activates the enzyme. With a tenfold excess of titanium(III) citrate at pH 8.0 the activator can be further reduced, yielding about 50% of a superreduced [4Fe–4S]0 cluster in the all-ferrous state. This is inferred from the appearance of a new Mössbauer spectrum with parameters δ = 0.65 mm/s and ΔEQ = 1.51–2.19 mm/s at 140 K, which are typical of Fe(II)S4 sites. Parallel-mode electron paramagnetic resonance (EPR) spectroscopy performed at temperatures between 3 and 20 K showed two sharp signals at g = 16 and 12, indicating an integer-spin system. The X-band EPR spectra and magnetic Mössbauer spectra could be consistently simulated by adopting a total spin St = 4 for the all-ferrous cluster with weak zero-field splitting parameters D = −0.66 cm−1 and E/D = 0.17. The superreduced cluster has apparent spectroscopic similarities with the corresponding [4Fe–4S]0 cluster described for the nitrogenase Fe-protein, but in detail their properties differ. While the all-ferrous Fe-protein is capable of transferring electrons to the MoFe-protein for dinitrogen reduction, a similar physiological role is elusive for the superreduced activator. This finding supports our model that only one-electron transfer steps are involved in dehydratase catalysis. Nevertheless we discuss a common basic mechanism of the two diverse systems, which are so far the only described examples of the all-ferrous [4Fe–4S]0 cluster found in biology

Corporation taxes in the European Union: Slowly moving toward comprehensive business income taxation?

This paper is a substantial revision of a paper presented at the 71st Annual Congress of the International Institute of Public Finance (Dublin, 20–23 August, 2015), which was issued under the title Tackling Spillovers by Taxing Corporate Income in the European Union at Source, as CPB Discussion Paper 324 (February 2016) and as CESifo Working Paper No. 5790 (March 2016).This paper surveys and evaluates the corporation tax systems of the Member States of the European Union on the basis of a comprehensive taxonomy of actual and potential regimes, which have as their base either profits; profits, interest and royalties; or economic rents. The current regimes give rise to various instate and interstate spillovers, which violate the basic tenets—neutrality and subsidiarity—of the single market. The trade-offs between the implications of these tenets—harmonization and diversity, respectively—can be reconciled by a bottom-up strategy of strengthening source-based taxation and narrowing differences in tax rates. The strategy starts with dual income taxation, proceeds with final source withholding taxes and rate coordination, and is made complete by comprehensive business income taxation. Common base and cash flow taxation are not favored.http://link.springer.com/journal/10797am2017Economic

Musgrave’s vision of the public sector: the complex relationship between individual, society and state in public good theory

Public Goods, Merit Wants, Collective Actions, H, H3,

The relative decline of a Musgrave ‘Merit Good:’ the case of public support of flagship public universities

Merit Good, Externalities, Higher Education, H21, H23, H24,

The Role of Government and Trust in the Market Economy

This paper studies the role of governments and its link to trust. We argue that the public’s trust strongly depends on governments delivering on their core tasks in a market economy. In some economies, a neglect of core tasks can be observed and there seems to be some erosion, notably in terms of securing sound rules of the game in industrialised countries. We find very little correlation between government expenditure and trust but a strong correlation with delivering on core tasks. This leads us to conclude that it is not government spending per se that needs to increase to build trust, but rather better focused government activities

Merit Goods

International audienc