RRC ID 6168
Author Pye VE, Christensen CE, Dyer JH, Arent S, Henriksen A.
Title Peroxisomal plant 3-ketoacyl-CoA thiolase structure and activity are regulated by a sensitive redox switch.
Journal J Biol Chem
Abstract The breakdown of fatty acids, performed by the beta-oxidation cycle, is crucial for plant germination and sustainability. beta-Oxidation involves four enzymatic reactions. The final step, in which a two-carbon unit is cleaved from the fatty acid, is performed by a 3-ketoacyl-CoA thiolase (KAT). The shortened fatty acid may then pass through the cycle again (until reaching acetoacetyl-CoA) or be directed to a different cellular function. Crystal structures of KAT from Arabidopsis thaliana and Helianthus annuus have been solved to 1.5 and 1.8 A resolution, respectively. Their dimeric structures are very similar and exhibit a typical thiolase-like fold; dimer formation and active site conformation appear in an open, active, reduced state. Using an interdisciplinary approach, we confirmed the potential of plant KATs to be regulated by the redox environment in the peroxisome within a physiological range. In addition, co-immunoprecipitation studies suggest an interaction between KAT and the multifunctional protein that is responsible for the preceding two steps in beta-oxidation, which would allow a route for substrate channeling. We suggest a model for this complex based on the bacterial system.
Volume 285(31)
Pages 24078-88
Published 2010-7-30
DOI 10.1074/jbc.M110.106013
PII M110.106013
PMID 20463027
PMC PMC2911321
MeSH Acetyl-CoA C-Acyltransferase / chemistry* Arabidopsis / enzymology* Cloning, Molecular Crystallography, X-Ray / methods Dimerization Fatty Acids / chemistry Gene Expression Regulation, Enzymologic Gene Expression Regulation, Plant Helianthus / enzymology* Lipids / chemistry Models, Biological Oxidation-Reduction* Oxygen / chemistry Peroxisomes / enzymology* Substrate Specificity
IF 4.106
Times Cited 20
Arabidopsis / Cultured plant cells, genes pda03502