Shiv K. Sah-Teli, Mikko J. Hynönen, Ramita Sulu, Subhadra Dalwani, Werner Schmitz, Rik K. Wierenga, Rajaram Venkatesan, Insights into the stability and substrate specificity of the E. coli aerobic β-oxidation trifunctional enzyme complex, Journal of Structural Biology, Volume 210, Issue 3, 2020, 107494, ISSN 1047-8477, https://doi.org/10.1016/j.jsb.2020.107494
Insights into the stability and substrate specificity of the E. coli aerobic β-oxidation trifunctional enzyme complex
|Author:||Sah-Teli, Shiv K.1; Hynönen, Mikko J.1; Sulu, Ramita1;|
1Faculty of Biochemistry and Molecular Medicine, and Biocenter Oulu, University of Oulu, Oulu, Finland
2Theoder-Boveri-Institut für Biowissenschaften der Universität Würzburg, Würzburg, Germany
|Persistent link:|| http://urn.fi/urn:nbn:fi-fe2020052639154
|Publish Date:|| 2021-03-11
Degradation of fatty acids by the β-oxidation pathway results in the formation of acetyl-CoA which enters the TCA cycle for the production of ATP. In E. coli, the last three steps of the β-oxidation are catalyzed by two heterotetrameric α₂β₂ enzymes namely the aerobic trifunctional enzyme (EcTFE) and the anaerobic TFE (anEcTFE). The α-subunit of TFE has 2E-enoyl-CoA hydratase (ECH) and 3S-hydroxyacyl-CoA dehydrogenase (HAD) activities whereas the β-subunit is a thiolase with 3-ketoacyl-CoA thiolase (KAT) activity. Recently, it has been shown that the two TFEs have complementary substrate specificities allowing for the complete degradation of long chain fatty acyl-CoAs into acetyl-CoA under aerobic conditions. Also, it has been shown that the tetrameric EcTFE and anEcTFE assemblies are similar to the TFEs of Pseudomans fragi and human, respectively. Here the properties of the EcTFE subunits are further characterized. Strikingly, it is observed that when expressed separately, EcTFE-α is a catalytically active monomer whereas EcTFE-β is inactive. However, when mixed together active EcTFE tetramer is reconstituted. The crystal structure of the EcTFE-α chain is also reported, complexed with ATP, bound in its HAD active site. Structural comparisons show that the EcTFE hydratase active site has a relatively small fatty acyl tail binding pocket when compared to other TFEs in good agreement with its preferred specificity for short chain 2E-enoyl-CoA substrates. Furthermore, it is observed that millimolar concentrations of ATP destabilize the EcTFE complex, and this may have implications for the ATP-mediated regulation of β-oxidation in E. coli.
Journal of structural biology
|Type of Publication:||
A1 Journal article – refereed
|Field of Science:||
1182 Biochemistry, cell and molecular biology
The work was supported by funding from Academy of Finland (grant numbers 293369, 289024 and 319194). Part of this work was also supported by iNEXT Project 653706 funded by the Horizon 2020 program of the European Union.
|EU Grant Number:||
(653706) iNEXT - Infrastructure for NMR, EM and X-rays for translational research
|Academy of Finland Grant Number:||
293369 (Academy of Finland Funding decision)
289024 (Academy of Finland Funding decision)
319194 (Academy of Finland Funding decision)
© 2020 Elsevier Inc. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/.