Cover Picture: Engineered SAM Synthetases for Enzymatic Generation of AdoMet Analogs with Photocaging Groups and Reversible DNA Modification in Cascade Reactions (Angew. Chem. Int. Ed. 1/2021)

Sequence-specific modification (“writing”) and light-triggered removal (“erasing”) of DNA is reported for the first time in an enzymatic cascade. In their Research Article on page 480, Andrea Rentmeister and co-workers engineered SAM synthetases suitable for converting methionine analogs with photo-cleavable groups and show their compatibility with methyltransferases to provide DNA with a light-sensitive “cage”. Crystal structure analysis revealed how substitutions in the active site led to accommodation of the photo-cleavable group.