9icd: Difference between revisions
No edit summary |
No edit summary |
||
| Line 1: | Line 1: | ||
[[Image:9icd.gif|left|200px]] | [[Image:9icd.gif|left|200px]] | ||
'''CATALYTIC MECHANISM OF NADP+-DEPENDENT ISOCITRATE DEHYDROGENASE: IMPLICATIONS FROM THE STRUCTURES OF MAGNESIUM-ISOCITRATE AND NADP+ COMPLEXES''' | {{Structure | ||
|PDB= 9icd |SIZE=350|CAPTION= <scene name='initialview01'>9icd</scene>, resolution 2.5Å | |||
|SITE= | |||
|LIGAND= <scene name='pdbligand=NAP:NADP NICOTINAMIDE-ADENINE-DINUCLEOTIDE PHOSPHATE'>NAP</scene> | |||
|ACTIVITY= [http://en.wikipedia.org/wiki/Isocitrate_dehydrogenase_(NADP(+)) Isocitrate dehydrogenase (NADP(+))], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.1.1.42 1.1.1.42] | |||
|GENE= | |||
}} | |||
'''CATALYTIC MECHANISM OF NADP+-DEPENDENT ISOCITRATE DEHYDROGENASE: IMPLICATIONS FROM THE STRUCTURES OF MAGNESIUM-ISOCITRATE AND NADP+ COMPLEXES''' | |||
==Overview== | ==Overview== | ||
| Line 7: | Line 16: | ||
==About this Structure== | ==About this Structure== | ||
9ICD is a [ | 9ICD is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=9ICD OCA]. | ||
==Reference== | ==Reference== | ||
Catalytic mechanism of NADP(+)-dependent isocitrate dehydrogenase: implications from the structures of magnesium-isocitrate and NADP+ complexes., Hurley JH, Dean AM, Koshland DE Jr, Stroud RM, Biochemistry. 1991 Sep 3;30(35):8671-8. PMID:[http:// | Catalytic mechanism of NADP(+)-dependent isocitrate dehydrogenase: implications from the structures of magnesium-isocitrate and NADP+ complexes., Hurley JH, Dean AM, Koshland DE Jr, Stroud RM, Biochemistry. 1991 Sep 3;30(35):8671-8. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/1888729 1888729] | ||
[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Isocitrate dehydrogenase (NADP(+))]] | [[Category: Isocitrate dehydrogenase (NADP(+))]] | ||
| Line 21: | Line 30: | ||
[[Category: oxidoreductase (nad(a)-choh(d))]] | [[Category: oxidoreductase (nad(a)-choh(d))]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 19:16:24 2008'' | ||
Revision as of 20:16, 20 March 2008
| |||||||
| , resolution 2.5Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | |||||||
| Activity: | Isocitrate dehydrogenase (NADP(+)), with EC number 1.1.1.42 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
CATALYTIC MECHANISM OF NADP+-DEPENDENT ISOCITRATE DEHYDROGENASE: IMPLICATIONS FROM THE STRUCTURES OF MAGNESIUM-ISOCITRATE AND NADP+ COMPLEXES
OverviewOverview
The structures of NADP+ and magnesium isocitrate bound to the NADP(+)-dependent isocitrate dehydrogenase of Escherichia coli have been determined and refined at 2.5-A resolution. NADP+ is bound by the large domain of isocitrate dehydrogenase, a structure that has little similarity to the supersecondary structure of the nucleotide-binding domain of the lactate dehydrogenase-like family of nucleotide-binding proteins. The coenzyme-binding site confirms the fundamentally different evolution of the isocitrate dehydrogenase-like and the lactate dehydrogenase-like classes of nucleotide-binding proteins. In the magnesium-isocitrate complex, magnesium is coordinated to the alpha-carboxylate and alpha-hydroxyl oxygen of isocitrate in a manner suitable for stabilization of a negative charge on the hydroxyl oxygen during both the dehydrogenation and decarboxylation steps of the conversion of isocitrate to alpha-ketoglutarate. The metal ion is also coordinated by aspartate side chains 283' (of the second subunit of the dimer) and 307 and two water molecules in a roughly octahedral arrangement. On the basis of the geometry of the active site, the base functioning in the dehydrogenation step is most likely aspartate 283'. E. coli isocitrate dehydrogenase transfers a hydride stereospecifically to the A-side of NADP+, and models for a reactive ternary complex consistent with this stereospecificity are discussed.
About this StructureAbout this Structure
9ICD is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
ReferenceReference
Catalytic mechanism of NADP(+)-dependent isocitrate dehydrogenase: implications from the structures of magnesium-isocitrate and NADP+ complexes., Hurley JH, Dean AM, Koshland DE Jr, Stroud RM, Biochemistry. 1991 Sep 3;30(35):8671-8. PMID:1888729
Page seeded by OCA on Thu Mar 20 19:16:24 2008