2jap
From Proteopedia
| Line 4: | Line 4: | ||
==Overview== | ==Overview== | ||
| - | The ultimate step in the biosynthesis of the medicinally important | + | The ultimate step in the biosynthesis of the medicinally important beta-lactamase inhibitor clavulanic acid is catalyzed by clavulanic acid dehydrogenase (CAD). CAD is responsible for the NAPDH-dependent reduction of the unstable intermediate clavulanate-9-aldehyde to yield clavulanic acid. Here, we report biochemical and structural studies on CAD. Biophysical analyses demonstrate that CAD exists as dimeric and tetrameric species in solution. The reaction performed by CAD was shown to be reversible, allowing the use of clavulanic acid for activity analyses. The crystal structure of CAD was solved using single-wavelength anomalous diffraction with a seleno-methionine derivative. The structure reveals that the individual monomers comprise a single domain possessing the Rossmann fold, characteristic of dinucleotide-binding enzymes. The monomers are arranged as tetramers, similar to other tetrameric members of the short-chain dehydrogenase/reductase family. The structure of the unreactive complex of CAD with clavulanic acid and NADPH suggests how CAD is able to catalyze the reduction of clavulanate-9-aldehyde without fragmentation of the bicyclic beta-lactam ring structure. The relative positions of NADPH and clavulanic acid, in the active site, together with the presence of the latter in an eclipsed conformation, rationalizes previous labeling studies demonstrating that the incorporation of the C5 pro-R, but not pro-S, hydrogen of ornithine/arginine into the C9 position of clavulanic acid occurs with overall inversion of configuration. |
==About this Structure== | ==About this Structure== | ||
| Line 15: | Line 15: | ||
[[Category: Andersson, I.]] | [[Category: Andersson, I.]] | ||
[[Category: Hernandez, H.]] | [[Category: Hernandez, H.]] | ||
| - | [[Category: Kershaw, N | + | [[Category: Kershaw, N J.]] |
| - | [[Category: Mackenzie, A | + | [[Category: Mackenzie, A K.]] |
| - | [[Category: Robinson, C | + | [[Category: Robinson, C V.]] |
| - | [[Category: Schofield, C | + | [[Category: Schofield, C J.]] |
[[Category: J01]] | [[Category: J01]] | ||
[[Category: NDP]] | [[Category: NDP]] | ||
| Line 27: | Line 27: | ||
[[Category: short-chain dehydrogenase/reductase]] | [[Category: short-chain dehydrogenase/reductase]] | ||
| - | ''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 18:01:08 2008'' |
Revision as of 16:01, 21 February 2008
|
CLAVULANIC ACID DEHYDROGENASE: STRUCTURAL AND BIOCHEMICAL ANALYSIS OF THE FINAL STEP IN THE BIOSYNTHESIS OF THE BETA-LACTAMASE INHIBITOR CLAVULANIC ACID
Overview
The ultimate step in the biosynthesis of the medicinally important beta-lactamase inhibitor clavulanic acid is catalyzed by clavulanic acid dehydrogenase (CAD). CAD is responsible for the NAPDH-dependent reduction of the unstable intermediate clavulanate-9-aldehyde to yield clavulanic acid. Here, we report biochemical and structural studies on CAD. Biophysical analyses demonstrate that CAD exists as dimeric and tetrameric species in solution. The reaction performed by CAD was shown to be reversible, allowing the use of clavulanic acid for activity analyses. The crystal structure of CAD was solved using single-wavelength anomalous diffraction with a seleno-methionine derivative. The structure reveals that the individual monomers comprise a single domain possessing the Rossmann fold, characteristic of dinucleotide-binding enzymes. The monomers are arranged as tetramers, similar to other tetrameric members of the short-chain dehydrogenase/reductase family. The structure of the unreactive complex of CAD with clavulanic acid and NADPH suggests how CAD is able to catalyze the reduction of clavulanate-9-aldehyde without fragmentation of the bicyclic beta-lactam ring structure. The relative positions of NADPH and clavulanic acid, in the active site, together with the presence of the latter in an eclipsed conformation, rationalizes previous labeling studies demonstrating that the incorporation of the C5 pro-R, but not pro-S, hydrogen of ornithine/arginine into the C9 position of clavulanic acid occurs with overall inversion of configuration.
About this Structure
2JAP 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
Clavulanic acid dehydrogenase: structural and biochemical analysis of the final step in the biosynthesis of the beta-lactamase inhibitor clavulanic acid., MacKenzie AK, Kershaw NJ, Hernandez H, Robinson CV, Schofield CJ, Andersson I, Biochemistry. 2007 Feb 13;46(6):1523-33. Epub 2007 Jan 19. PMID:17279617
Page seeded by OCA on Thu Feb 21 18:01:08 2008
