1cq1: Difference between revisions

[[Image:1cq1.gif|left|200px]]<br /><applet load="1cq1" size="350" color="white" frame="true" align="right" spinBox="true"  

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.

1CQ1 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Acinetobacter_calcoaceticus Acinetobacter calcoaceticus] with <scene name='pdbligand=GLC:'>GLC</scene>, <scene name='pdbligand=CA:'>CA</scene> and <scene name='pdbligand=PQQ:'>PQQ</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. The following page contains interesting information on the relation of 1CQ1 with [[http://pdb.rcsb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/pdb77_1.html Glucose Oxidase]]. Active as [http://en.wikipedia.org/wiki/Quinoprotein_glucose_dehydrogenase Quinoprotein glucose dehydrogenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.1.5.2 1.1.5.2] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1CQ1 OCA].  

[[Category: Dijkstra, B W.]]

[[Category: Rozeboom, H J.]]

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