2jib
From Proteopedia
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==Overview== | ==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 . | + | 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== | ||
| - | 2JIB is a | + | 2JIB is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Oxalobacter_formigenes Oxalobacter formigenes] with MG, COA, TPP, ADP and PGE as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Oxalyl-CoA_decarboxylase Oxalyl-CoA decarboxylase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.1.1.8 4.1.1.8] Structure known Active Site: AC1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=2JIB OCA]. |
==Reference== | ==Reference== | ||
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[[Category: thiamine pyrophosphate]] | [[Category: thiamine pyrophosphate]] | ||
| - | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 5 13:30:21 2007'' |
Revision as of 11:25, 5 November 2007
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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 MG, COA, TPP, ADP and PGE as ligands. Active as Oxalyl-CoA decarboxylase, with EC number 4.1.1.8 Structure known Active Site: AC1. 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 Mon Nov 5 13:30:21 2007
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
