The crystal structure of mouse phosphoglucose isomerase at 1.6A resolution and its complex with glucose 6-phosphate reveals the catalytic mechanism of sugar ring opening.

Phosphoglucose isomerase (PGI) is an enzyme of glycolysis that interconverts glucose 6-phosphate (G6P) and fructose 6-phosphate (F6P) but, outside the cell, is a multifunctional cytokine. High-resolution crystal structures of the enzyme from mouse have been determined in native form and in complex with the inhibitor erythrose 4-phosphate, and with the substrate glucose 6-phosphate. In the substrate-bound structure, the glucose sugar is observed in both straight-chain and ring forms.

The structure of human phosphoglucose isomerase complexed with a transition-state analogue.

Phosphoglucose isomerase (PGI) is a workhorse enzyme of carbohydrate metabolism that interconverts glucose 6-phosphate and fructose 6-phosphate. Outside the cell, however, the protein appears to function as a cytokine. A crystal structure of human PGI bound with 5-phosphoarabinonate, a strong inhibitor that mimics the cis-enediol(ate) intermediate of the reaction, has been determined at 2.

Structure of native phosphoglucose isomerase from rabbit: conformational changes associated with catalytic function.

Phosphoglucose isomerase (PGI) is a housekeeping enzyme of metabolism that catalyses the interconversion of glucose 6-phosphate and fructose 6-phosphate, with roles in the glycolytic and gluconeogenic pathways. PGI is also a multifunctional protein that manifests the properties of a cytokine in a wide array of cellular processes, including the production of immunoglobulin by B cells and tumour-cell differentiation. The crystal structure of PGI in the native form from rabbit muscle has been solved at a resolution of 2.

The crystal structure of human phosphoglucose isomerase at 1.6 A resolution: implications for catalytic mechanism, cytokine activity and haemolytic anaemia.

Phosphoglucose isomerase (PGI) is a multifunctional protein, which, inside the cell, functions as a housekeeping enzyme of glycolysis and gluconeogenesis and, outside the cell, exerts wholly unrelated cytokine properties. We have determined the structure of human PGI to a resolution of 1.6 A using X-ray crystallography.