Functions of the conserved anionic amino acids and those interacting with the substrate phosphate group of phosphoglucose isomerase

Phosphoglucose isomerase catalyzes the isomerization isomerization glucose 6-phosphate and fructose 6-phosphate in cytoplasm, and functions as autocri ne motility factor and neuroleukin outside the tells. A phosphoglucose isom erase from Bacillus stearothermophilus (pgiA) was subjected to mutagenesis study to address the catalytic function of the conserved anionic residues a nd those probably interacting with the phosphate group of substrates. The r esults suggest that Glu290 works concertedly with His311 as a general acid- base pair to initiate the isomerization step, and Glu150 assists the base f unction of His311. The conserved loop structure consisting of Gly205-Gly206 -Arg207 plays a critical role for the recognition of substrates. (C) 2001 F ederation of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved.