STRUCTURES OF APO AND COMPLEXED ESCHERICHIA-COLI GLYCINAMIDE RIBONUCLEOTIDE TRANSFORMYLASE

The three-dimensional structure of phosphoribosylglycinamide formyltransferase (10-formyltetrahydrofolate:5'-phosphoribosylglycinamide formyltransferase, EC 2.1.2.2) has been solved both as an apoenzyme at 2.8-angstrom resolution and as a ternary complex with the substrate glycinamide ribonucleotide and a folate inhibitor at 2.5-angstrom resolution. The structure is a modified doubly wound alpha/beta-sheet with flexibility in the active site, including a disordered loop in the apo structure, which is ordered in the ternary complex structure. This enzyme is a target for anti-cancer therapy and now for structure-based drug design.