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

J Biol Chem. 2006 Oct 13;281(41):31012-20. doi: 10.1074/jbc.M603405200. Epub 2006 Aug 3.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acyl-CoA Dehydrogenase / chemistry*
  • Acyl-CoA Oxidase / chemistry*
  • Arabidopsis / enzymology*
  • Arabidopsis Proteins / chemistry*
  • Electrons
  • Models, Molecular
  • Oxygen / chemistry
  • Plant Proteins / chemistry
  • Protein Binding
  • Protein Conformation
  • Protein Structure, Secondary
  • Protein Structure, Tertiary
  • Static Electricity
  • Substrate Specificity


  • Arabidopsis Proteins
  • Plant Proteins
  • ACX4 protein, Arabidopsis
  • Acyl-CoA Oxidase
  • Acyl-CoA Dehydrogenase
  • Oxygen

Associated data

  • PDB/2IX5
  • PDB/2IX6