1e5h
From Proteopedia
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==Overview== | ==Overview== | ||
| - | Deacetoxycephalosporin C synthase (DAOCS) is an iron(II) and | + | Deacetoxycephalosporin C synthase (DAOCS) is an iron(II) and 2-oxoglutarate-dependent oxygenase that catalyzes the conversion of penicillin N to deacetoxycephalosporin C, the committed step in the biosynthesis of cephalosporin antibiotics. The crystal structure of DAOCS revealed that the C terminus of one molecule is inserted into the active site of its neighbor in a cyclical fashion within a trimeric unit. This arrangement has hindered the generation of crystalline enzyme-substrate complexes. Therefore, we constructed a series of DAOCS mutants with modified C termini. Oxidation of 2-oxoglutarate was significantly uncoupled from oxidation of the penicillin substrate in certain truncated mutants. The extent of uncoupling varied with the number of residues deleted and the penicillin substrate used. Crystal structures were determined for the DeltaR306 mutant complexed with iron(II) and 2-oxoglutarate (to 2.10 A) and the DeltaR306A mutant complexed with iron(II), succinate and unhydrated carbon dioxide (to 1.96 A). The latter may mimic a product complex, and supports proposals for a metal-bound CO(2) intermediate during catalysis. |
==About this Structure== | ==About this Structure== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Streptomyces clavuligerus]] | [[Category: Streptomyces clavuligerus]] | ||
| - | [[Category: Baldwin, J | + | [[Category: Baldwin, J E.]] |
| - | [[Category: Clifton, I | + | [[Category: Clifton, I J.]] |
[[Category: Harlos, K.]] | [[Category: Harlos, K.]] | ||
| - | [[Category: Lee, H | + | [[Category: Lee, H J.]] |
| - | [[Category: Lloyd, M | + | [[Category: Lloyd, M D.]] |
| - | [[Category: Schofield, C | + | [[Category: Schofield, C J.]] |
[[Category: CO2]] | [[Category: CO2]] | ||
[[Category: FE2]] | [[Category: FE2]] | ||
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[[Category: oxidoreductase]] | [[Category: oxidoreductase]] | ||
| - | ''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 12:24:08 2008'' |
Revision as of 10:24, 21 February 2008
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DELTA-R307A DEACETOXYCEPHALOSPORIN C SYNTHASE COMPLEXED WITH SUCCINATE AND CARBON DIOXIDE
Overview
Deacetoxycephalosporin C synthase (DAOCS) is an iron(II) and 2-oxoglutarate-dependent oxygenase that catalyzes the conversion of penicillin N to deacetoxycephalosporin C, the committed step in the biosynthesis of cephalosporin antibiotics. The crystal structure of DAOCS revealed that the C terminus of one molecule is inserted into the active site of its neighbor in a cyclical fashion within a trimeric unit. This arrangement has hindered the generation of crystalline enzyme-substrate complexes. Therefore, we constructed a series of DAOCS mutants with modified C termini. Oxidation of 2-oxoglutarate was significantly uncoupled from oxidation of the penicillin substrate in certain truncated mutants. The extent of uncoupling varied with the number of residues deleted and the penicillin substrate used. Crystal structures were determined for the DeltaR306 mutant complexed with iron(II) and 2-oxoglutarate (to 2.10 A) and the DeltaR306A mutant complexed with iron(II), succinate and unhydrated carbon dioxide (to 1.96 A). The latter may mimic a product complex, and supports proposals for a metal-bound CO(2) intermediate during catalysis.
About this Structure
1E5H is a Single protein structure of sequence from Streptomyces clavuligerus with , and as ligands. Known structural/functional Site: . Full crystallographic information is available from OCA.
Reference
Kinetic and crystallographic studies on deacetoxycephalosporin C synthase (DAOCS)., Lee HJ, Lloyd MD, Harlos K, Clifton IJ, Baldwin JE, Schofield CJ, J Mol Biol. 2001 May 18;308(5):937-48. PMID:11352583
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