Bifunctional glucose-6-phosphate/mannose-6-phosphate isomerase, C-terminal (IPR019490)

Short name: Glu6P/Mann6P_isomerase_C

Overlapping homologous superfamilies


Domain relationships



Phosphoglucose isomerase (PGI) catalyses the interconversion of phosphoglucose and phosphofructose, and is a component of many sugar metabolic pathways. In some archaea and bacteria PGI activity occurs via a bifunctional enzyme that also exhibits phosphomannose isomerase (PMI) activity. Though not closely related to eukaryotic PGIs, the bifunctional enzyme is similar enough that the sequence includes the cluster of threonines and serines that forms the sugar phosphate-binding site in conventional PGI.

The bifunctional PGI/PMI enzyme contains two SIS (Sugar ISomerase) domains. This entry represents the C-terminal SIS domain, which contains many of the active catalytic site residues. The enzyme is thought to use the same catalytic mechanisms for both glucose ring-opening and isomerisation for the interconversion of glucose 6-phosphate to fructose 6-phosphate [PMID: 15252053].

GO terms

Biological Process

GO:0005975 carbohydrate metabolic process

Molecular Function

GO:0004347 glucose-6-phosphate isomerase activity
GO:0004476 mannose-6-phosphate isomerase activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.