Named after Selene, goddess of the moon selenocysteine (Sec) is unique in its unrivaled catalytic power and its insertion into proteins by redefinition of specific UGA stop codons to Sec. In their Communication on page 319 ff., D. Söll, P. O'Donoghue et al. describe the engineering of the Sec-insertion machinery to redefine nearly all 64 codons. Here, the ring-shaped decameric selenocysteine synthase SeIA is essential in providing tRNA-bound Sec as the central building block for selenoprotein translation.
In their Communication on page 122 ff., W. Xing, X. L. Hu et al. describe a novel Pd–Ni2P/C electrocatalyst that gives superior performance to a state-of-the-art commercial Pd/C catalyst for the oxidation of formic acid in fuel cells.
T. Weil and co-workers describe dendrimer-coated enzymes in their Communication on page 324 ff. These structurally defined biohybrids show pH-responsive activity and the capability for membrane translocation and localization.
B. A. Grzybowski, M. O. de la Cruz et al. present the self-replication of light-sensitive nanoparticle dimers in their Communication on page 173 ff. What matters is not constant energetic expenditure but the timing with which energy is delivered to the system.