51_06/2012Cover Picture: Crystal Structure of Methylornithine Synthase (PylB): Insights into the Pyrrolysine Biosynthesis (Angew. Chem. Int. Ed. 6/2012)

The unusual amino acid pyrrolysine is found in the active site of the methylamine methyltransferases of certain methanogenic archaea. Methylornithine, an intermediate in pyrrolysine biosynthesis, is formed by the PylB-catalyzed isomerization of lysine. In their Communication on page 1339 ff., M. Groll and co-workers present the crystal structure of PylB in complex with its reaction product and suggest a fragmentation–recombination mechanism via a glycyl radical intermediate.

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Also of Interest

Alkane Activation by Bacteriafor001

H. Wilkes et al. investigate the anaerobic C-H activation of n-alkanes by bacteria in their Communication on page 1334 ff. The reaction occurs stereospecifically, and the mechanism is in complete contrast to the known oxidation of alkanes by oxygenases.


Origami of Hydrogel Bilayersfor002

In their Communication on page 1420 ff., S.-M. Yang and co-workers show planar bilayer microparticles composed of active and passive layers that can transform into microcapsules with a closed compartment.


Hydrated Ionic Liquidsfor003

In their Communication on page 1416 ff., H. Tateishi-Karimata and N. Sugimoto show that A–T base pairs are more stable than G–C base pairs in an ionic liquid.


51_06i/2012Inside Cover: Host–Guest Geometry in Pores of Zeolite ZSM-5 Spatially Resolved with Multiplex CARS Spectromicroscopy (Angew. Chem. Int. Ed. 6/2012)

The spatial arrangement of molecules in zeolite pores plays a crucial role in determining the overall catalytic activity of the system. In their Communication on page 1343 ff., K. F. Domke et al. give unique insight on the correlation between the geometry and reactivity of thiophene derivatives adsorbed in ZSM-5. In images obtained by coherent anti-Stokes Raman scattering (CARS) spectromicroscopy, chains of reagent molecules in the pores are resolved and the structural anisotropy of the zeolite is evident.

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51_06b/2012Back Cover: A–T Base Pairs are More Stable Than G–C Base Pairs in a Hydrated Ionic Liquid (Angew. Chem. Int. Ed. 6/2012)

Hydrated ionic liquids are “green” solvents suitable for a wide range of reactions. In their Communication on page 1416 ff., H. Tateishi-Karimata and N. Sugimoto show that A–T base pairs are more stable than G–C base pairs in choline dihydrogenphosphate because of specific interactions between the DNA bases and choline ions. Understanding the stabilities of Watson–Crick base pairs in this environmentally friendly solvent will be critical as nano-biotechnology applications of DNA advance.

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