1xi2
Quinone Reductase 2 in Complex with Cancer Prodrug CB1954Quinone Reductase 2 in Complex with Cancer Prodrug CB1954
Structural highlights
Function[NQO2_HUMAN] The enzyme apparently serves as a quinone reductase in connection with conjugation reactions of hydroquinones involved in detoxification pathways as well as in biosynthetic processes such as the vitamin K-dependent gamma-carboxylation of glutamate residues in prothrombin synthesis.[1] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedCB1954 is a cancer pro-drug that can be activated through reduction by Escherichia coli nitro-reductases and quinone reductases. Human quinone reductase 2 is very efficient in the activation of CB1954, approximately 3000 times more efficient than human QR1 in terms of k(cat)/K(m). We have solved the three-dimensional structure of QR2 in complex with CB1954 to a nominal resolution of 1.5A. The complex structure indicates the essentiality of the two nitro groups: one nitro group forms hydrogen bonds with the side-chain of Asn161 of QR2 to hold the other nitro group in position for the reduction. We further conclude that residue 161, an Asn in QR2 and a His in QR1, is critical in differentiating the substrate specificities of these two enzymes. Mutation of Asn161 to His161 in QR2 resulted in the total loss of the enzymatic activity towards activation of CB1954, whereas the rates of reduction towards menadione are not altered. Crystal structure of quinone reductase 2 in complex with cancer prodrug CB1954.,Fu Y, Buryanovskyy L, Zhang Z Biochem Biophys Res Commun. 2005 Oct 14;336(1):332-8. PMID:16129418[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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