Soluble glucose dehydrogenase (s-GDH) from the bacterium Acinetobacter calcoaceticus is a classical quinoprotein. It requires the cofactor pyrroloquinoline quinone (PQQ) to catalyze the oxidation of glucose to gluconolactone. The precise catalytic role of PQQ in s-GDH and several other PQQ-dependent enzymes has remained controversial because of the absence of comprehensive structural data ...
Soluble glucose dehydrogenase (s-GDH) from the bacterium Acinetobacter calcoaceticus is a classical quinoprotein. It requires the cofactor pyrroloquinoline quinone (PQQ) to catalyze the oxidation of glucose to gluconolactone. The precise catalytic role of PQQ in s-GDH and several other PQQ-dependent enzymes has remained controversial because of the absence of comprehensive structural data. We have determined the crystal structure of a ternary complex of s-GDH with PQQ and methylhydrazine, a competitive inhibitor of the enzyme. This complex, refined at 1.5-A resolution to an R factor of 16.7%, affords a detailed view of a cofactor-binding site of s-GDH. Moreover, it presents the first direct observation of covalent PQQ adduct in the active-site of a PQQ-dependent enzyme, thereby confirming previous evidence that the C5 carbonyl group of the cofactor is the most reactive moiety of PQQ.
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
Structure and Mechanism of Soluble Quinoprotein Glucose Dehydrogenase Oubrie, A., Rozeboom, H.J., Kalk, K.H., Olsthoorn, A.J.J., Duine, J.A., Dijsktra, B.W. () To be published --: --
Organizational Affiliation:
Laboratory of Biophysical Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
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