The two analogous phosphoglycerate mutases of Escherichia coli

The glycolytic enzyme phosphoglycerate mutase exists in two evolutionarily unrelated forms. Vertebrates have only the 2,3-bisphosphoglycerate-dependen t enzyme (dPGM), whilst higher plants have only the cofactor-independent en zyme (iPGM). Certain eubacteria possess genes encoding both enzymes, and th eir respective metabolic roles and activities are unclear. We have over-exp ressed, purified and characterised the two PGMs of Escherichia coli, Both a re expressed at high levels, but dPGM has a 10-fold higher specific activit y than iPGM. Differential inhibition by vanadate was observed, The presence of an integral manganese ion in iPGM was confirmed by EPR spectroscopy. (C ) 1999 Federation of European Biochemical Societies.