2ii4: Difference between revisions
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'''Crystal structure of a cubic core of the dihydrolipoamide acyltransferase (E2b) component in the branched-chain alpha-ketoacid dehydrogenase complex (BCKDC), Coenzyme A-bound form''' | {{Structure | ||
|PDB= 2ii4 |SIZE=350|CAPTION= <scene name='initialview01'>2ii4</scene>, resolution 2.590Å | |||
|SITE= | |||
|LIGAND= <scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene> and <scene name='pdbligand=COA:COENZYME A'>COA</scene> | |||
|ACTIVITY= [http://en.wikipedia.org/wiki/Dihydrolipoyllysine-residue_(2-methylpropanoyl)transferase Dihydrolipoyllysine-residue (2-methylpropanoyl)transferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.3.1.168 2.3.1.168] | |||
|GENE= DBT ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9913 Bos taurus]) | |||
}} | |||
'''Crystal structure of a cubic core of the dihydrolipoamide acyltransferase (E2b) component in the branched-chain alpha-ketoacid dehydrogenase complex (BCKDC), Coenzyme A-bound form''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
2II4 is a [ | 2II4 is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2II4 OCA]. | ||
==Reference== | ==Reference== | ||
A synchronized substrate-gating mechanism revealed by cubic-core structure of the bovine branched-chain alpha-ketoacid dehydrogenase complex., Kato M, Wynn RM, Chuang JL, Brautigam CA, Custorio M, Chuang DT, EMBO J. 2006 Dec 13;25(24):5983-94. Epub 2006 Nov 23. PMID:[http:// | A synchronized substrate-gating mechanism revealed by cubic-core structure of the bovine branched-chain alpha-ketoacid dehydrogenase complex., Kato M, Wynn RM, Chuang JL, Brautigam CA, Custorio M, Chuang DT, EMBO J. 2006 Dec 13;25(24):5983-94. Epub 2006 Nov 23. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/17124494 17124494] | ||
[[Category: Bos taurus]] | [[Category: Bos taurus]] | ||
[[Category: Dihydrolipoyllysine-residue (2-methylpropanoyl)transferase]] | [[Category: Dihydrolipoyllysine-residue (2-methylpropanoyl)transferase]] | ||
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[[Category: homo trimer]] | [[Category: homo trimer]] | ||
''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 17:29:56 2008'' | ||
Revision as of 18:29, 20 March 2008
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| , resolution 2.590Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | and | ||||||
| Gene: | DBT (Bos taurus) | ||||||
| Activity: | Dihydrolipoyllysine-residue (2-methylpropanoyl)transferase, with EC number 2.3.1.168 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Crystal structure of a cubic core of the dihydrolipoamide acyltransferase (E2b) component in the branched-chain alpha-ketoacid dehydrogenase complex (BCKDC), Coenzyme A-bound form
OverviewOverview
The dihydrolipoamide acyltransferase (E2b) component of the branched-chain alpha-ketoacid dehydrogenase complex forms a cubic scaffold that catalyzes acyltransfer from S-acyldihydrolipoamide to CoA to produce acyl-CoA. We have determined the first crystal structures of a mammalian (bovine) E2b core domain with and without a bound CoA or acyl-CoA. These structures reveal both hydrophobic and the previously unreported ionic interactions between two-fold-related trimers that build up the cubic core. The entrance of the dihydrolipoamide-binding site in a 30-A long active-site channel is closed in the apo and acyl-CoA-bound structures. CoA binding to one entrance of the channel promotes a conformational change in the channel, resulting in the opening of the opposite dihydrolipoamide gate. Binding experiments show that the affinity of the E2b core for dihydrolipoamide is markedly increased in the presence of CoA. The result buttresses the model that CoA binding is responsible for the opening of the dihydrolipoamide gate. We suggest that this gating mechanism synchronizes the binding of the two substrates to the active-site channel, which serves as a feed-forward switch to coordinate the E2b-catalyzed acyltransfer reaction.
About this StructureAbout this Structure
2II4 is a Single protein structure of sequence from Bos taurus. Full crystallographic information is available from OCA.
ReferenceReference
A synchronized substrate-gating mechanism revealed by cubic-core structure of the bovine branched-chain alpha-ketoacid dehydrogenase complex., Kato M, Wynn RM, Chuang JL, Brautigam CA, Custorio M, Chuang DT, EMBO J. 2006 Dec 13;25(24):5983-94. Epub 2006 Nov 23. PMID:17124494
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