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1dxo
From Proteopedia
| 1dxo, resolution 2.50Å () | |||||||||
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| Ligands: | , | ||||||||
| Activity: | NAD(P)H dehydrogenase (quinone), with EC number 1.6.5.2 | ||||||||
| Domains: | Flavodoxin_2 | ||||||||
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| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||||
CRYSTAL STRUCTURE OF HUMAN NAD[P]H-QUINONE OXIDOREDUCTASE CO WITH 2,3,5,6,TETRAMETHYL-P-BENZOQUINONE (DUROQUINONE) AT 2.5 ANGSTROM RESOLUTION
(see also NADH quinone oxidoreductase (NQO1) with inhibitor dicoumarol)
NAD(P)H/quinone acceptor oxidoreductase (QR1, NQO1, formerly DT-diaphorase; EC ) protects animal cells from the deleterious and carcinogenic effects of quinones and other electrophiles. In this paper we report the apoenzyme structures of human (at 1.7-A resolution) and mouse (2.8 A) QR1 and the complex of the human enzyme with the substrate duroquinone (2.5 A) (2,3,5, 6-tetramethyl-p-benzoquinone). In addition to providing a description and rationale of the structural and catalytic differences among several species, these structures reveal the changes that accompany substrate or cofactor (NAD) binding and release. Tyrosine-128 and the loop spanning residues 232-236 close the binding site, partially occupying the space left vacant by the departing molecule (substrate or cofactor). These changes highlight the exquisite control of access to the catalytic site that is required by the ping-pong mechanism in which, after reducing the flavin, NAD(P)(+) leaves the catalytic site and allows substrate to bind at the vacated position. In the human QR1-duroquinone structure one ring carbon is significantly closer to the flavin N5, suggesting a direct hydride transfer to this atom.
Structures of recombinant human and mouse NAD(P)H:quinone oxidoreductases: species comparison and structural changes with substrate binding and release., Faig M, Bianchet MA, Talalay P, Chen S, Winski S, Ross D, Amzel LM, Proc Natl Acad Sci U S A. 2000 Mar 28;97(7):3177-82. PMID:10706635
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
About this Structure
1DXO is a 4 chains structure of sequences from Homo sapiens. Full crystallographic information is available from OCA.
Reference
- Faig M, Bianchet MA, Talalay P, Chen S, Winski S, Ross D, Amzel LM. Structures of recombinant human and mouse NAD(P)H:quinone oxidoreductases: species comparison and structural changes with substrate binding and release. Proc Natl Acad Sci U S A. 2000 Mar 28;97(7):3177-82. PMID:10706635
Page seeded by OCA on Tue Feb 17 23:50:44 2009
