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The crystal structure of a plant 3-ketoacyl-CoA thiolase reveals the potential for redox control of peroxisomal fatty acid β-oxidation
Citation
Sundaramoorthy, R and Micossi, E and Alphey, MS and Germain, V and Bryce, JH and Smith, SM and Leonard, GA and Hunter, WN, The crystal structure of a plant 3-ketoacyl-CoA thiolase reveals the potential for redox control of peroxisomal fatty acid β-oxidation, Journal of Molecular Biology, 359, (2) pp. 347-357. ISSN 0022-2836 (2006) [Refereed Article]
Copyright Statement
Copyright 2006 Elsevier
DOI: doi:10.1016/j.jmb.2006.03.032
Abstract
Crystal structures of peroxisomal Arabidopsis thaliana 3-ketoacyl-CoA thiolase (AtKAT), an enzyme of fatty acid β-oxidation, are reported. The subunit, a typical thiolase, is a combination of two similar α/β domains capped with a loop domain. The comparison of AtKAT with the Saccharomyces cerevisiae homologue (ScKAT) structure reveals a different placement of subunits within the functional dimers and that a polypeptide segment forming an extended loop around the open catalytic pocket of ScKAT converts to α-helix in AtKAT, and occludes the active site. A disulfide is formed between Cys192, on this helix, and Cys138, a catalytic residue. Access to Cys138 is determined by the structure of this polypeptide segment. AtKAT represents an oxidized, previously unknown inactive form, whilst ScKAT is the reduced and active enzyme. A high level of sequence conservation is observed, including Cys192, in eukaryotic peroxisomal, but not mitochondrial or prokaryotic KAT sequences, for this labile loop/helix segment. This indicates that KAT activity in peroxisomes is influenced by a disulfide/dithiol change linking fatty acid β-oxidation with redox regulation.
Item Details
Item Type: | Refereed Article |
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Keywords: | arabidopsis thaliana, 3-ketoacyl-CoA thiolase, fatty acid beta-oxidation |
Research Division: | Biological Sciences |
Research Group: | Plant biology |
Research Field: | Plant physiology |
Objective Division: | Expanding Knowledge |
Objective Group: | Expanding knowledge |
Objective Field: | Expanding knowledge in the biological sciences |
UTAS Author: | Smith, SM (Professor Steven Smith) |
ID Code: | 101513 |
Year Published: | 2006 |
Web of Science® Times Cited: | 18 |
Deposited By: | Plant Science |
Deposited On: | 2015-06-25 |
Last Modified: | 2018-03-19 |
Downloads: | 0 |
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