1ek4
From Proteopedia
| Line 4: | Line 4: | ||
|PDB= 1ek4 |SIZE=350|CAPTION= <scene name='initialview01'>1ek4</scene>, resolution 1.85Å | |PDB= 1ek4 |SIZE=350|CAPTION= <scene name='initialview01'>1ek4</scene>, resolution 1.85Å | ||
|SITE= | |SITE= | ||
| - | |LIGAND= <scene name='pdbligand=DAO:LAURIC ACID'>DAO</scene> | + | |LIGAND= <scene name='pdbligand=DAO:LAURIC+ACID'>DAO</scene> |
| - | |ACTIVITY= [http://en.wikipedia.org/wiki/Beta-ketoacyl-acyl-carrier-protein_synthase_I Beta-ketoacyl-acyl-carrier-protein synthase I], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.3.1.41 2.3.1.41] | + | |ACTIVITY= <span class='plainlinks'>[http://en.wikipedia.org/wiki/Beta-ketoacyl-acyl-carrier-protein_synthase_I Beta-ketoacyl-acyl-carrier-protein synthase I], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.3.1.41 2.3.1.41] </span> |
|GENE= | |GENE= | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY=[[1dd8|1DD8]] | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1ek4 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ek4 OCA], [http://www.ebi.ac.uk/pdbsum/1ek4 PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1ek4 RCSB]</span> | ||
}} | }} | ||
| Line 28: | Line 31: | ||
[[Category: Siggaard-Andersen, M.]] | [[Category: Siggaard-Andersen, M.]] | ||
[[Category: Wettstein-Knowles, P von.]] | [[Category: Wettstein-Knowles, P von.]] | ||
| - | [[Category: DAO]] | ||
[[Category: claisen condensation]] | [[Category: claisen condensation]] | ||
[[Category: fatty acid substrate complex]] | [[Category: fatty acid substrate complex]] | ||
| Line 34: | Line 36: | ||
[[Category: thiolase fold]] | [[Category: thiolase fold]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 20:04:11 2008'' |
Revision as of 17:04, 30 March 2008
| |||||||
| , resolution 1.85Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | |||||||
| Activity: | Beta-ketoacyl-acyl-carrier-protein synthase I, with EC number 2.3.1.41 | ||||||
| Related: | 1DD8
| ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
BETA-KETOACYL [ACYL CARRIER PROTEIN] SYNTHASE I IN COMPLEX WITH DODECANOIC ACID TO 1.85 RESOLUTION
Overview
BACKGROUND: beta-ketoacyl-acyl carrier protein synthase (KAS) I is vital for the construction of the unsaturated fatty acid carbon skeletons characterizing E. coli membrane lipids. The new carbon-carbon bonds are created by KAS I in a Claisen condensation performed in a three-step enzymatic reaction. KAS I belongs to the thiolase fold enzymes, of which structures are known for five other enzymes. RESULTS: Structures of the catalytic Cys-Ser KAS I mutant with covalently bound C10 and C12 acyl substrates have been determined to 2.40 and 1.85 A resolution, respectively. The KAS I dimer is not changed by the formation of the complexes but reveals an asymmetric binding of the two substrates bound to the dimer. A detailed model is proposed for the catalysis of KAS I. Of the two histidines required for decarboxylation, one donates a hydrogen bond to the malonyl thioester oxo group, and the other abstracts a proton from the leaving group. CONCLUSIONS: The same mechanism is proposed for KAS II, which also has a Cys-His-His active site triad. Comparison to the active site architectures of other thiolase fold enzymes carrying out a decarboxylation step suggests that chalcone synthase and KAS III with Cys-His-Asn triads use another mechanism in which both the histidine and the asparagine interact with the thioester oxo group. The acyl binding pockets of KAS I and KAS II are so similar that they alone cannot provide the basis for their differences in substrate specificity.
About this Structure
1EK4 is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
Structures of beta-ketoacyl-acyl carrier protein synthase I complexed with fatty acids elucidate its catalytic machinery., Olsen JG, Kadziola A, von Wettstein-Knowles P, Siggaard-Andersen M, Larsen S, Structure. 2001 Mar 7;9(3):233-43. PMID:11286890
Page seeded by OCA on Sun Mar 30 20:04:11 2008
