Controlling Electron Transfer in Acyl-Coa Oxidases and Dehydrogenases: A Structural View.Mackenzie, J., Pedersen, L., Arent, S., Henriksen, A.
(2006) J Biol Chem 281: 31012
- PubMed: 16887802
- DOI: https://doi.org/10.1074/jbc.M603405200
- Primary Citation of Related Structures:
- PubMed 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.
Biostructure Group, Carlsberg Laboratory, Gamle Carlsberg Vej 10, DK-2500 Valby, Denmark.