1IYZ
Crystal Structures of the Quinone Oxidoreductase from Thermus thermophilus HB8 and Its Complex with NADPH
Summary for 1IYZ
| Entry DOI | 10.2210/pdb1iyz/pdb |
| Descriptor | QUINONE OXIDOREDUCTASE, NADPH DIHYDRO-NICOTINAMIDE-ADENINE-DINUCLEOTIDE PHOSPHATE (3 entities in total) |
| Functional Keywords | protein-nadph complex, riken structural genomics/proteomics initiative, rsgi, structural genomics, oxidoreductase |
| Biological source | Thermus thermophilus |
| Total number of polymer chains | 1 |
| Total formula weight | 32872.08 |
| Authors | Shimomura, Y.,Kakuta, Y.,Fukuyama, K.,RIKEN Structural Genomics/Proteomics Initiative (RSGI) (deposition date: 2002-09-17, release date: 2003-07-15, Last modification date: 2023-12-27) |
| Primary citation | Shimomura, Y.,Kakuta, Y.,Fukuyama, K. Crystal Structures of the Quinone Oxidoreductase from Thermus thermophilus HB8 and Its Complex with NADPH: Implication for NADPH and Substrate Recognition J.Bacteriol., 185:4211-4218, 2003 Cited by PubMed Abstract: The crystal structures of the zeta-crystalline-like soluble quinone oxidoreductase from Thermus thermophilus HB8 (QOR(Tt)) and of its complex with NADPH have been determined at 2.3- and 2.8-A resolutions, respectively. QOR(Tt) is composed of two domains, and its overall fold is similar to the folds of Escherichia coli quinone oxidoreductase (QOR(Ec)) and horse liver alcohol dehydrogenase. QOR(Tt) forms a homodimer in the crystal by interaction of the betaF-strands in domain II, forming a large beta-sheet that crosses the dimer interface. High thermostability of QOR(Tt) was evidenced by circular dichroic measurement. NADPH is located between the two domains in the QOR(Tt)-NADPH complex. The disordered segment involved in the coenzyme binding of apo-QOR(Tt) becomes ordered upon NADPH binding. The segment covers an NADPH-binding cleft and may serve as a lid. The 2'-phosphate group of the adenine of NADPH is surrounded by polar and positively charged residues in QOR(Tt), suggesting that QOR(Tt) binds NADPH more readily than NADH. The putative substrate-binding site of QOR(Tt), unlike that of QOR(Ec), is largely blocked by nearby residues, permitting access only to small substrates. This may explain why QOR(Tt) has weak p-benzoquinone reduction activity and is inactive with such large substrates of QOR(Ec) as 5-hydroxy-1,4-naphthoquinone and phenanthraquinone. PubMed: 12837796DOI: 10.1128/JB.185.14.4211-4218.2003 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.8 Å) |
Structure validation
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