The first Fe(ii)- and 2-oxoglutarate (2OG)-dependent oxygenases to be identified were the animal pro-collagen hydroxylases (see Chapter 5).^1–3  However, to date the oxygenase domains of these enzymes have proven to be rather recalcitrant with respect to high-resolution structural studies. Instead, the first crystal structure of a member of this superfamily (henceforth simplified to the 2OG oxygenases) came from work on enzymes involved in the biosynthesis of the β-lactam antibiotics.^4–6  This work was enabled by contemporary advances in molecular biology, which allowed the production of unnaturally large amounts of protein in recombinant hosts. The first structure of...