1tzc
Crystal structure of phosphoglucose/phosphomannose isomerase from Pyrobaculum aerophilum in complex with 5-phosphoarabinonateCrystal structure of phosphoglucose/phosphomannose isomerase from Pyrobaculum aerophilum in complex with 5-phosphoarabinonate
Structural highlights
Function[PGMI_PYRAE] Catalyzes the isomerization of both glucose 6-phosphate and epimeric mannose 6-phosphate at a similar catalytic efficiency. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe crystal structure of a dual specificity phosphoglucose isomerase (PGI)/phosphomannose isomerase from Pyrobaculum aerophilum (PaPGI/PMI) has been determined in native form at 1.16-A resolution and in complex with the enzyme inhibitor 5-phosphoarabinonate at 1.45-A resolution. The similarity of its fold, with the inner core structure of PGIs from eubacterial and eukaryotic sources, confirms this enzyme as a member of the PGI superfamily. The almost total conservation of amino acids in the active site, including the glutamate base catalyst, shows that PaPGI/PMI uses the same catalytic mechanisms for both ring opening and isomerization for the interconversion of glucose 6-phosphate (Glc-6-P) to fructose 6-phosphate (Fru-6-P). The lack of structural differences between native and inhibitor-bound enzymes suggests this activity occurs without any of the conformational changes that are the hallmark of the well characterized PGI family. The lack of a suitable second base in the active site of PaPGI/PMI argues against a PMI mechanism involving a trans-enediol intermediate. Instead, PMI activity may be the result of additional space in the active site imparted by a threonine, in place of a glutamine in other PGI enzymes, which could permit rotation of the C-2-C-3 bond of mannose 6-phosphate. A novel phosphoglucose isomerase (PGI)/phosphomannose isomerase from the crenarchaeon Pyrobaculum aerophilum is a member of the PGI superfamily: structural evidence at 1.16-A resolution.,Swan MK, Hansen T, Schonheit P, Davies C J Biol Chem. 2004 Sep 17;279(38):39838-45. Epub 2004 Jul 13. PMID:15252053[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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