1CQ1

Soluble Quinoprotein Glucose Dehydrogenase from Acinetobacter Calcoaceticus in Complex with PQQH2 and Glucose

Summary for 1CQ1

• Entry DOI: 10.2210/pdb1cq1/pdb
• Related: 1C9U 1CRU 1QBI
• Descriptor: SOLUBLE QUINOPROTEIN GLUCOSE DEHYDROGENASE, beta-D-glucopyranose, CALCIUM ION, ... (5 entities in total)
• Functional Keywords: beta-propeller, superbarrel, complex with cofactor and substrate, oxidoreductase
• Biological source: Acinetobacter calcoaceticus
• Total number of polymer chains: 2
• Total formula weight: 101847.61

Authors

Oubrie, A.,Rozeboom, H.J.,Dijkstra, B.W. (deposition date: 1999-08-04, release date: 2000-02-04, Last modification date: 2024-10-30)

Primary citation

Oubrie, A.,Rozeboom, H.J.,Kalk, K.H.,Olsthoorn, A.J.,Duine, J.A.,Dijkstra, B.W.
Structure and mechanism of soluble quinoprotein glucose dehydrogenase.
EMBO J., 18:5187-5194, 1999

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. 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.

PubMed: 10508152
DOI: 10.1093/emboj/18.19.5187

Experimental method

X-RAY DIFFRACTION (1.9 Å)