1IKA
STRUCTURE OF ISOCITRATE DEHYDROGENASE WITH ALPHA-KETOGLUTARATE AT 2.7 ANGSTROMS RESOLUTION: CONFORMATIONAL CHANGES INDUCED BY DECARBOXYLATION OF ISOCITRATE
1IKA の概要
エントリーDOI | 10.2210/pdb1ika/pdb |
分子名称 | ISOCITRATE DEHYDROGENASE, CALCIUM ION, 2-OXOGLUTARIC ACID (3 entities in total) |
機能のキーワード | oxidoreductase(nad(a)-choh(d)) |
由来する生物種 | Escherichia coli |
タンパク質・核酸の鎖数 | 1 |
化学式量合計 | 45995.74 |
構造登録者 | |
主引用文献 | Stoddard, B.L.,Koshland Jr., D.E. Structure of isocitrate dehydrogenase with alpha-ketoglutarate at 2.7-A resolution: conformational changes induced by decarboxylation of isocitrate. Biochemistry, 32:9317-9322, 1993 Cited by PubMed Abstract: The structure of the isocitrate dehydrogenase (IDH) complex with bound alpha-ketoglutarate, Ca2+, and NADPH was solved at 2.7-A resolution. The alpha-ketoglutarate binds in the active site at the same position and orientation as isocitrate, with a difference between the two bound molecules of about 0.8 A. The Ca2+ metal is coordinated by alpha-ketoglutarate, three conserved aspartate residues, and a pair of water molecules. The largest motion in the active site relative to the isocitrate enzyme complex is observed for tyrosine 160, which originally forms a hydrogen bond to the labile carboxyl group of isocitrate and moves to form a new hydrogen bond to Asp 307 in the complex with alpha-ketoglutarate. This triggers a number of significant movements among several short loops and adjoining secondary structural elements in the enzyme, most of which participate in dimer stabilization and formation of the active-site cleft. These rearrangements are similar to the ligand-binding-induced movements observed in globins and insulin and serve as a model for an enzymatic mechanism which involves local shifts of secondary structural elements during turnover, rather than large-scale domain closures or loop transitions induced by substrate binding such as those observed in hexokinase or triosephosphate isomerase. PubMed: 8369301DOI: 10.1021/bi00087a009 主引用文献が同じPDBエントリー |
実験手法 | X-RAY DIFFRACTION (2.7 Å) |
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