FIGURE 1. Enzymes by design.

Röthlisberger et al.¹ have computationally designed and prepared the first enzyme capable of catalysing a non-biological reaction. Here, the computational model (grey) is overlaid with the crystal structure of the actual protein (green); the two overlap almost perfectly. The substrate is shown at the centre of the structure. The design process involved modifying the amino-acid sequence of a naturally occurring protein. Residues selected computationally to form the active site are shown as purple spheres. Additional mutations that were introduced in vitro to optimize the enzyme's performance are shown as green spheres.