Primary Citation of Related Structures: 1C9U, 1CQ1
PubMed Abstract:
Soluble glucose dehydrogenase (s-GDH; EC 1.1.99.17) is a classical quinoprotein which requires the cofactor pyrroloquinoline quinone (PQQ) to oxidize glucose to gluconolactone. The reaction mechanism of PQQ-dependent enzymes has remained controversial due to the absence of comprehensive structural data ...
Soluble glucose dehydrogenase (s-GDH; EC 1.1.99.17) is a classical quinoprotein which requires the cofactor pyrroloquinoline quinone (PQQ) to oxidize glucose to gluconolactone. The reaction mechanism of PQQ-dependent enzymes has remained controversial due to the absence of comprehensive structural data. We have determined the X-ray structure of s-GDH with the cofactor at 2.2 A resolution, and of a complex with reduced PQQ and glucose at 1.9 A resolution. These structures reveal the active site of s-GDH, and show for the first time how a functionally bound substrate interacts with the cofactor in a PQQ-dependent enzyme. Twenty years after the discovery of PQQ, our results finally provide conclusive evidence for a reaction mechanism comprising general base-catalyzed hydride transfer, rather than the generally accepted covalent addition-elimination mechanism. Thus, PQQ-dependent enzymes use a mechanism similar to that of nicotinamide- and flavin-dependent oxidoreductases.
Related Citations:
The 1.7 Angstrom crystal structure of the apo form of the soluble quinoprotein glucose dehydrogenase from Acinetobacter calcoaceticus reveals a novel internal sequence repeat Oubrie, A., Rozeboom, H.J., Kalk, K.H., Duine, J.A., Dijkstra, B.W. (1999) J Mol Biol 289: 319
Organizational Affiliation:
Laboratory of Biophysical Chemistry and BIOSON Research Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen.
Download Mendeley
