Phosphoglucose Isomerase (PGI) is an enzyme crucial for the interconversion of D-glucose 6-phosphate and D-fructose 6-phosphate. PGI is responsible for the second step of glycolysis and is involved in glucogenesis. It is highly conserved in bacteria and eukaryotes.http://www.creative-enzymes.com/product/Native-Bakers-Yeast-S-Cerevisiae-Phosphoglucose-Isomerase_1379.html