Also catalyzes the anomerization of D-glucose 6-phosphate.

Phosphoglucose isomerase is a dimeric enzyme that catalyzes the reversible isomerization of glucose-6-phosphate and fructose-6- phosphate. PGI is involved in different pathways: in most higher organisms it is involved in glycolysis; in mammals it is involved in gluconeogenesis; in plants in carbohydrate biosynthesis; in some bacteria it provides a gateway for fructose into the Entner-Doudouroff pathway. PGI has been shown to be identical to neuroleukin, a neurotrophic factor which supports the survival of various types of neurons.

The sequence of PGI from many species ranging from bacteria to mammals is available and has been shown to be highly conserved. As signature patterns for this enzyme it has been selected two conserved regions, the first region is located in the central section of PGI, while the second one is located in its C-terminal section.
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