2jib
From Proteopedia
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==Overview== | ==Overview== | ||
| - | Despite more than five decades of extensive studies of thiamin diphosphate | + | Despite more than five decades of extensive studies of thiamin diphosphate (ThDP) enzymes, there remain many uncertainties as to how these enzymes achieve their rate enhancements. Here, we present a clear picture of catalysis for the simple nonoxidative decarboxylase, oxalyl-coenzyme A (CoA) decarboxylase, based on crystallographic snapshots along the catalytic cycle and kinetic data on active site mutants. First, we provide crystallographic evidence that, upon binding of oxalyl-CoA, the C-terminal 13 residues fold over the substrate, aligning the substrate alpha-carbon for attack by the ThDP-C2 atom. The second structure presented shows a covalent reaction intermediate after decarboxylation, interpreted as being nonplanar. Finally, the structure of a product complex is presented. In accordance with mutagenesis data, no side chains of the enzyme are implied to directly participate in proton transfer except the glutamic acid (Glu-56), which promotes formation of the 1',4'-iminopyrimidine tautomer of ThDP needed for activation. |
==About this Structure== | ==About this Structure== | ||
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[[Category: Oxalyl-CoA decarboxylase]] | [[Category: Oxalyl-CoA decarboxylase]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Berthold, C | + | [[Category: Berthold, C L.]] |
[[Category: Leeper, F.]] | [[Category: Leeper, F.]] | ||
[[Category: Lindqvist, Y.]] | [[Category: Lindqvist, Y.]] | ||
[[Category: Moussatche, P.]] | [[Category: Moussatche, P.]] | ||
| - | [[Category: Richards, N | + | [[Category: Richards, N G.J.]] |
| - | [[Category: Toyota, C | + | [[Category: Toyota, C G.]] |
| - | [[Category: Wood, M | + | [[Category: Wood, M D.]] |
[[Category: ADP]] | [[Category: ADP]] | ||
[[Category: COA]] | [[Category: COA]] | ||
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[[Category: thiamine pyrophosphate]] | [[Category: thiamine pyrophosphate]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 18:03:35 2008'' |
Revision as of 16:03, 21 February 2008
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X-RAY STRUCTURE OF OXALYL-COA DECARBOXYLASE IN COMPLEX WITH COENZYME-A
Overview
Despite more than five decades of extensive studies of thiamin diphosphate (ThDP) enzymes, there remain many uncertainties as to how these enzymes achieve their rate enhancements. Here, we present a clear picture of catalysis for the simple nonoxidative decarboxylase, oxalyl-coenzyme A (CoA) decarboxylase, based on crystallographic snapshots along the catalytic cycle and kinetic data on active site mutants. First, we provide crystallographic evidence that, upon binding of oxalyl-CoA, the C-terminal 13 residues fold over the substrate, aligning the substrate alpha-carbon for attack by the ThDP-C2 atom. The second structure presented shows a covalent reaction intermediate after decarboxylation, interpreted as being nonplanar. Finally, the structure of a product complex is presented. In accordance with mutagenesis data, no side chains of the enzyme are implied to directly participate in proton transfer except the glutamic acid (Glu-56), which promotes formation of the 1',4'-iminopyrimidine tautomer of ThDP needed for activation.
About this Structure
2JIB is a Single protein structure of sequence from Oxalobacter formigenes with , , , and as ligands. Active as Oxalyl-CoA decarboxylase, with EC number 4.1.1.8 Known structural/functional Site: . Full crystallographic information is available from OCA.
Reference
Crystallographic snapshots of oxalyl-CoA decarboxylase give insights into catalysis by nonoxidative ThDP-dependent decarboxylases., Berthold CL, Toyota CG, Moussatche P, Wood MD, Leeper F, Richards NG, Lindqvist Y, Structure. 2007 Jul;15(7):853-61. PMID:17637344
Page seeded by OCA on Thu Feb 21 18:03:35 2008
Categories: Oxalobacter formigenes | Oxalyl-CoA decarboxylase | Single protein | Berthold, C L. | Leeper, F. | Lindqvist, Y. | Moussatche, P. | Richards, N G.J. | Toyota, C G. | Wood, M D. | ADP | COA | MG | PGE | TPP | Decarboxylase | Flavoprotein | Lyase | Non- oxidative decarboxylase | Oxalate degradation | Substrate complex | Thiamin diphosphate-dependent | Thiamine pyrophosphate
