PROSITE documentation PDOC00157Glucose-6-phosphate isomerase (GPI) family signatures and profile
Glucose-6-phosphate isomerase (GPI) (EC 5.3.1.9) or phosphoglucose isomerase (PGI) [1,2] 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. Besides it's role as a glycolytic enzyme, mammalian PGI can function as a tumor-secreted cytokine and an angiogenic factor (AMF) that stimulates endothelial cell motility. Mammalian PGI is also neuroleukin [3], a neurotrophic factor which supports the survival of various types of neurons.
The sequence of PGI is conserved among diverse species ranging from bacteria to mammals and structures form a similar fold (see <PDB:1IAT>) [4,5], comprised of two subdomains that each form an α-β-α sandwich, with the active site located in the cleft between the subdomains and on the dimer interface. A glutamate and a lysine residue as well as a histidine from the other protomer in the dimer are implicated in the catalytic mechanism. The structure resembles that of the SIS domain (see <PDOC51464>).
As signature patterns for this enzyme we 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. We also developed a profile that covers the entire PGI.
Last update:September 2009 / Text revised; profile added.
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PROSITE methods (with tools and information) covered by this documentation:
| 1 | Authors | Achari A. Marshall S.E. Muirhead H. Palmieri R.H. Noltmann E.A. |
| Title | Glucose-6-phosphate isomerase. | |
| Source | Philos. Trans. R. Soc. Lond., B, Biol. Sci. 293:145-157(1981). | |
| PubMed ID | 6115414 |
| 2 | Authors | Smith M.W. Doolittle R.F. |
| Title | Anomalous phylogeny involving the enzyme glucose-6-phosphate isomerase. | |
| Source | J. Mol. Evol. 34:544-545(1992). | |
| PubMed ID | 1593646 |
| 3 | Authors | Faik P. Walker J.I.H. Redmill A.A.M. Morgan M.J. |
| Title | Mouse glucose-6-phosphate isomerase and neuroleukin have identical 3' sequences. | |
| Source | Nature 332:455-457(1988). | |
| PubMed ID | 3352745 | |
| DOI | 10.1038/332455a0 |
| 4 | Authors | Read J. Pearce J. Li X. Muirhead H. Chirgwin J. Davies C. |
| Title | The crystal structure of human phosphoglucose isomerase at 1.6 A resolution: implications for catalytic mechanism, cytokine activity and haemolytic anaemia. | |
| Source | J. Mol. Biol. 309:447-463(2001). | |
| PubMed ID | 11371164 | |
| DOI | 10.1006/jmbi.2001.4680 |
| 5 | Authors | Yamamoto H. Miwa H. Kunishima N. |
| Title | Crystal structure of glucose-6-phosphate isomerase from Thermus thermophilus HB8 showing a snapshot of active dimeric state. | |
| Source | J. Mol. Biol. 382:747-762(2008). | |
| PubMed ID | 18675274 | |
| DOI | 10.1016/j.jmb.2008.07.041 |
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