2c3d
From Proteopedia
| Line 5: | Line 5: | ||
==Overview== | ==Overview== | ||
| - | The structure of the mixed, enzyme-cofactor disulfide intermediate of, ketopropyl-coenzyme M oxidoreductase/carboxylase has been determined by, X-ray diffraction methods. Ketopropyl-coenzyme M, oxidoreductase/carboxylase belongs to a family of pyridine, nucleotide-containing flavin-dependent disulfide oxidoreductases, which, couple the transfer of hydride derived from the NADPH to the reduction of, protein cysteine disulfide. Ketopropyl-coenzyme M, oxidoreductase/carboxylase, a unique member of this enzyme class, catalyzes thioether bond cleavage of the substrate, 2-ketopropyl-coenzyme, M, and carboxylation of what is thought to be an enzyme-stabilized, enolacetone intermediate. The mixed disulfide of 2-ketopropyl-coenzyme M, oxidoreductase/carboxylase was captured through crystallization ... | + | The structure of the mixed, enzyme-cofactor disulfide intermediate of, ketopropyl-coenzyme M oxidoreductase/carboxylase has been determined by, X-ray diffraction methods. Ketopropyl-coenzyme M, oxidoreductase/carboxylase belongs to a family of pyridine, nucleotide-containing flavin-dependent disulfide oxidoreductases, which, couple the transfer of hydride derived from the NADPH to the reduction of, protein cysteine disulfide. Ketopropyl-coenzyme M, oxidoreductase/carboxylase, a unique member of this enzyme class, catalyzes thioether bond cleavage of the substrate, 2-ketopropyl-coenzyme, M, and carboxylation of what is thought to be an enzyme-stabilized, enolacetone intermediate. The mixed disulfide of 2-ketopropyl-coenzyme M, oxidoreductase/carboxylase was captured through crystallization of the, enzyme with the physiological products of the reaction, acetoacetate, coenzyme M, and NADP, and reduction of the crystals with dithiothreitol, just prior to data collection. Density in the active-site environment, consistent with acetone, the product of reductive decarboxylation of, acetoacetate, was revealed in this structure in addition to a well-defined, hydrophobic pocket or channel that could be involved in the access for, carbon dioxide. The analysis of this structure and that of a, coenzyme-M-bound form provides insights into the stabilization of, intermediates, substrate carboxylation, and product release. |
==About this Structure== | ==About this Structure== | ||
| - | 2C3D is a | + | 2C3D is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Xanthobacter_autotrophicus Xanthobacter autotrophicus] with FAD and COM as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/2-oxopropyl-CoM_reductase_(carboxylating) 2-oxopropyl-CoM reductase (carboxylating)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.8.1.5 1.8.1.5] Structure known Active Site: AC1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=2C3D OCA]. |
==Reference== | ==Reference== | ||
| Line 28: | Line 28: | ||
[[Category: redox-active center]] | [[Category: redox-active center]] | ||
| - | ''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 13:48:15 2007'' |
Revision as of 11:42, 5 November 2007
|
2.15 ANGSTROM CRYSTAL STRUCTURE OF 2-KETOPROPYL COENZYME M OXIDOREDUCTASE CARBOXYLASE WITH A COENZYME M DISULFIDE BOUND AT THE ACTIVE SITE
Overview
The structure of the mixed, enzyme-cofactor disulfide intermediate of, ketopropyl-coenzyme M oxidoreductase/carboxylase has been determined by, X-ray diffraction methods. Ketopropyl-coenzyme M, oxidoreductase/carboxylase belongs to a family of pyridine, nucleotide-containing flavin-dependent disulfide oxidoreductases, which, couple the transfer of hydride derived from the NADPH to the reduction of, protein cysteine disulfide. Ketopropyl-coenzyme M, oxidoreductase/carboxylase, a unique member of this enzyme class, catalyzes thioether bond cleavage of the substrate, 2-ketopropyl-coenzyme, M, and carboxylation of what is thought to be an enzyme-stabilized, enolacetone intermediate. The mixed disulfide of 2-ketopropyl-coenzyme M, oxidoreductase/carboxylase was captured through crystallization of the, enzyme with the physiological products of the reaction, acetoacetate, coenzyme M, and NADP, and reduction of the crystals with dithiothreitol, just prior to data collection. Density in the active-site environment, consistent with acetone, the product of reductive decarboxylation of, acetoacetate, was revealed in this structure in addition to a well-defined, hydrophobic pocket or channel that could be involved in the access for, carbon dioxide. The analysis of this structure and that of a, coenzyme-M-bound form provides insights into the stabilization of, intermediates, substrate carboxylation, and product release.
About this Structure
2C3D is a Single protein structure of sequence from Xanthobacter autotrophicus with FAD and COM as ligands. Active as 2-oxopropyl-CoM reductase (carboxylating), with EC number 1.8.1.5 Structure known Active Site: AC1. Full crystallographic information is available from OCA.
Reference
Mechanistic implications of the structure of the mixed-disulfide intermediate of the disulfide oxidoreductase, 2-ketopropyl-coenzyme M oxidoreductase/carboxylase., Pandey AS, Nocek B, Clark DD, Ensign SA, Peters JW, Biochemistry. 2006 Jan 10;45(1):113-20. PMID:16388586
Page seeded by OCA on Mon Nov 5 13:48:15 2007
