PMID: 16887802 , Related PDB ids: 2IX5, 2IX6

Authors:

Mackenzie J, Pedersen L, Arent S, Henriksen A

Title:

Controlling electron transfer in Acyl-CoA oxidases and dehydrogenases: a structural view.

Journal:

J Biol Chem. 2006 Oct 13;281(41):31012-20. Epub 2006 Aug 3.

Abstract:

Plants produce a unique peroxisomal short chain-specific acyl-CoA oxidase (ACX4) for beta-oxidation of lipids. The short chain-specific oxidase has little resemblance to other peroxisomal acyl-CoA oxidases but has an approximately 30% sequence identity to mitochondrial acyl-CoA dehydrogenases. Two biochemical features have been linked to structural properties by comparing the structures of short chain-specific Arabidopsis thaliana ACX4 with and without a substrate analogue bound in the active site to known acyl-CoA oxidases and dehydrogenase structures: (i) a solvent-accessible acyl binding pocket is not required for oxygen reactivity, and (ii) the oligomeric state plays a role in substrate pocket architecture but is not linked to oxygen reactivity. The structures indicate that the acyl-CoA oxidases may encapsulate the electrons for transfer to molecular oxygen by blocking the dehydrogenase substrate interaction site with structural extensions. A small binding pocket observed adjoining the flavin adenine dinucleotide N5 and C4a atoms could increase the number of productive encounters between flavin adenine dinucleotide and O2.