1x7n
The crystal structure of Pyrococcus furiosus phosphoglucose isomerase with bound 5-phospho-D-arabinonate and Manganese
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OverviewOverview
Pyrococcus furiosus phosphoglucose isomerase (PfPGI) is a metal-containing, enzyme that catalyses the interconversion of glucose 6-phosphate (G6P) and, fructose 6-phosphate (F6P). The recent structure of PfPGI has confirmed, the hypothesis that the enzyme belongs to the cupin superfamily and, identified the position of the active site. This fold is distinct from the, alphabetaalpha sandwich fold commonly seen in phosphoglucose isomerases, (PGIs) that are found in bacteria, eukaryotes and some archaea. Whilst the, mechanism of the latter family is thought to proceed through a cis-enediol, intermediate, analysis of the structure of PfPGI in the presence of, inhibitors has led to the suggestion that the mechanism of this enzyme, involves the metal-dependent direct transfer of a hydride between C1 and, C2 atoms of the substrate. To gain further insight in the reaction, mechanism of PfPGI, the structures of the free enzyme and the complexes, with the inhibitor, 5-phospho-d-arabinonate (5PAA) in the presence and, absence of metal have been determined. Comparison of these structures with, those of equivalent complexes of the eukaryotic PGIs reveals similarities, at the active site in the disposition of possible catalytic residues., These include the presence of a glutamic acid residue, Glu97 in PfPGI, which occupies the same position relative to the inhibitor as that of the, glutamate that is thought to function as the catalytic base in the, eukaryal-type PGIs. These similarities suggest that aspects of the, catalytic mechanisms of these two structurally unrelated PGIs may be, similar and based on an enediol intermediate.
About this StructureAbout this Structure
1X7N is a Single protein structure of sequence from Pyrococcus furiosus with MN and PA5 as ligands. Active as Glucose-6-phosphate isomerase, with EC number 5.3.1.9 Full crystallographic information is available from OCA.
ReferenceReference
The structures of inhibitor complexes of Pyrococcus furiosus phosphoglucose isomerase provide insights into substrate binding and catalysis., Berrisford JM, Akerboom J, Brouns S, Sedelnikova SE, Turnbull AP, van der Oost J, Salmon L, Hardre R, Murray IA, Blackburn GM, Rice DW, Baker PJ, J Mol Biol. 2004 Oct 22;343(3):649-57. PMID:15465052
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