PMID: 12573240

Authors:

Cordeiro AT, Godoi PH, Silva CH, Garratt RC, Oliva G, Thiemann OH

Title:

Crystal structure of human phosphoglucose isomerase and analysis of the initial catalytic steps.

Journal:

Biochim Biophys Acta. 2003 Feb 21;1645(2):117-22.

Abstract:

The second enzyme in the glycolytic pathway, phosphoglucose isomerase (PGI), catalyses an intracellular aldose-ketose isomerization. Here we describe the human recombinant PGI structure (hPGI) solved in the absence of active site ligands. Crystals isomorphous to those previously reported were used to collect a 94% complete data set to a limiting resolution of 2.1 A. From the comparison between the free active site hPGI structure and the available human and rabbit PGI (rPGI) structures, a mechanism for protein initial catalytic steps is proposed. Binding of the phosphate moiety of the substrate to two distinct elements of the active site is responsible for driving a series of structural changes resulting in the polarisation of the active site histidine, priming it for the initial ring-opening step of catalysis.