1TZC

Crystal structure of phosphoglucose/phosphomannose isomerase from Pyrobaculum aerophilum in complex with 5-phosphoarabinonate

Summary for 1TZC

• Entry DOI: 10.2210/pdb1tzc/pdb
• Related: 1TZB
• Descriptor: glucose-6-phosphate isomerase, conjectural, SULFATE ION, 5-PHOSPHOARABINONIC ACID, ... (5 entities in total)
• Functional Keywords: enzyme, crenarchaeon, hyperthermophile, pgi family, isomerase
• Biological source: Pyrobaculum aerophilum
• Total number of polymer chains: 2
• Total formula weight: 68338.49

Authors

Swan, M.K.,Hansen, T.,Schoenheit, P.,Davies, C. (deposition date: 2004-07-09, release date: 2004-07-20, Last modification date: 2024-04-03)

Primary citation

Swan, M.K.,Hansen, T.,Schoenheit, P.,Davies, C.
A novel phosphoglucose/phosphomannose isomease from the crenarchaeon Pyrobaculum aerophilum is a member of the PGI superfamily: structural evidence at 1.16 A resolution
J.Biol.Chem., 279:39838-39845, 2004

PubMed Abstract: The 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.

PubMed: 15252053
DOI: 10.1074/jbc.M406855200

Experimental method

X-RAY DIFFRACTION (1.45 Å)