Selective phosphoserine incorporation is described by H.-S. Park et al. in their Communication on page 5771 ff. A general strategy for producing recombinant histones with site-specific serine phosphorylation has been developed by engineering phosphoseryl-tRNA synthethase (SepRS) and elongation factor Tu (EF-Tu). This method should facilitate the study of histone phosphorylation and cross-regulatory mechanisms.
In their Communication on page 5726 ff., J. Tulla-Puche, F. Albericio, et al. describe the solid-phase synthesis of the complex cyclothiodepsipeptide thiocoraline. The applied phenylacetamidomethyl protecting group was cleaved by an immobilized enzyme.
In their Communication on page 5795 ff., Y. Huang et al. describe a general procedure for the synthesis of unprotected indoles. By using a cleavable triazene as the directing group, a CH annulation with excellent regioselectivity was accomplished.
The internalization of proteins and nanoparticles in living cells can be quantified by using a new DNA nanosensor, as described by A. P. R. Johnston and H. Liu on page 5744 ff. This technique enables multicolor assays and studies in primary cells without compromising sensitivity or quantification.