1wdk
fatty acid beta-oxidation multienzyme complex from Pseudomonas fragi, form I (native2)
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OverviewOverview
The atomic view of the active site coupling termed channelling is a major, subject in molecular biology. We have determined two distinct crystal, structures of the bacterial multienzyme complex that catalyzes the last, three sequential reactions in the fatty acid beta-oxidation cycle. The, alpha2beta2 heterotetrameric structure shows the uneven ring architecture, where all the catalytic centers of 2-enoyl-CoA hydratase (ECH), L-3-hydroxyacyl-CoA dehydrogenase (HACD) and 3-ketoacyl-CoA thiolase, (KACT) face a large inner solvent region. The substrate, anchored through, the 3'-phosphate ADP moiety, allows the fatty acid tail to pivot from the, ECH to HACD active sites, and finally to the KACT active site. Coupling, with striking domain rearrangements, the incorporation of the tail into, the KACT cavity and the relocation of 3'-phosphate ADP bring the reactive, C2-C3 bond to the correct position for cleavage. The alpha-helical linker, specific for the multienzyme contributes to the pivoting center formation, and the substrate transfer through its deformation. This channelling, mechanism could be applied to other beta-oxidation multienzymes, as, revealed from the homology model of the human mitochondrial trifunctional, enzyme complex.
About this StructureAbout this Structure
1WDK is a Protein complex structure of sequences from Pseudomonas fragi with HG, ZN, ACO, NAD and N8E as ligands. Active as Acetyl-CoA C-acyltransferase, with EC number 2.3.1.16 Full crystallographic information is available from OCA.
ReferenceReference
Structural basis for channelling mechanism of a fatty acid beta-oxidation multienzyme complex., Ishikawa M, Tsuchiya D, Oyama T, Tsunaka Y, Morikawa K, EMBO J. 2004 Jul 21;23(14):2745-54. Epub 2004 Jul 1. PMID:15229654
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