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1dwk
From Proteopedia
| 1dwk, resolution 1.65Å () | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Sites: | , , , , , , , , , , , , , , , , , , , , , , , , , , and | ||||||||
| Ligands: | , | ||||||||
| Non-Standard Residues: | |||||||||
| Activity: | Cyanase, with EC number 4.2.1.104 | ||||||||
| Related: | 1dw9 | ||||||||
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| Resources: | FirstGlance, OCA, PDBsum, RCSB, TOPSAN | ||||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||||
STRUCTURE OF CYANASE WITH THE DI-ANION OXALATE BOUND AT THE ENZYME ACTIVE SITE
BACKGROUND: Cyanase is an enzyme found in bacteria and plants that catalyzes the reaction of cyanate with bicarbonate to produce ammonia and carbon dioxide. In Escherichia coli, cyanase is induced from the cyn operon in response to extracellular cyanate. The enzyme is functionally active as a homodecamer of 17 kDa subunits, and displays half-site binding of substrates or substrate analogs. The enzyme shows no significant amino acid sequence homology with other proteins. RESULTS: We have determined the crystal structure of cyanase at 1.65 A resolution using the multiwavelength anomalous diffraction (MAD) method. Cyanase crystals are triclinic and contain one homodecamer in the asymmetric unit. Selenomethionine-labeled protein offers 40 selenium atoms for use in phasing. Structures of cyanase with bound chloride or oxalate anions, inhibitors of the enzyme, allowed identification of the active site. CONCLUSIONS: The cyanase monomer is composed of two domains. The N-terminal domain shows structural similarity to the DNA-binding alpha-helix bundle motif. The C-terminal domain has an 'open fold' with no structural homology to other proteins. The subunits of cyanase are arranged in a novel manner both at the dimer and decamer level. The dimer structure reveals the C-terminal domains to be intertwined, and the decamer is formed by a pentamer of these dimers. The active site of the enzyme is located between dimers and is comprised of residues from four adjacent subunits of the homodecamer. The structural data allow a conceivable reaction mechanism to be proposed.
Structure of cyanase reveals that a novel dimeric and decameric arrangement of subunits is required for formation of the enzyme active site., Walsh MA, Otwinowski Z, Perrakis A, Anderson PM, Joachimiak A, Structure. 2000 May 15;8(5):505-14. PMID:10801492
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
About this Structure
1DWK is a 10 chains structure of sequences from Escherichia coli. Full crystallographic information is available from OCA.
The structure of cyanase bound with chloride (1dw9) can also be found on this site.
Reference
- Walsh MA, Otwinowski Z, Perrakis A, Anderson PM, Joachimiak A. Structure of cyanase reveals that a novel dimeric and decameric arrangement of subunits is required for formation of the enzyme active site. Structure. 2000 May 15;8(5):505-14. PMID:10801492
Page seeded by OCA on Tue Feb 17 18:36:20 2009
Categories: Cyanase | Escherichia coli | Anderson, P M. | Joachimiak, A. | MCSG, Midwest Center for Structural Genomics. | Otwinowski, Z. | Perrakis, A. | Walsh, M A. | Cyanate degradation | Lyase | Mcsg | Midwest center for structural genomic | Protein structure initiative | Psi | Structural genomic
