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Updated: Sep 12, 2025
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Preparation and In Vivo Use of an Activity-based Probe for N-acylethanolamine Acid Amidase
Published on: November 23, 2016
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Structural Characterization of an Endogenous Algal Acyl-ACP Thioesterase.
Jeffrey A Chen1, Yixing Suo1, Stephen P Mayfield1
1Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0358, United States.
Biochemistry
|August 6, 2025
Summary
Researchers elucidated the mechanism of fatty acid chain-length determination by thioesterases in plants and algae. This discovery offers new strategies for engineering algae to produce specific fatty acids for biofuels and chemicals.
Area of Science:
- Biochemistry
- Molecular Biology
- Biotechnology
Background:
- Fatty acids of specific chain lengths are crucial precursors for renewable energy and fine chemicals.
- Thioesterase enzymes control fatty acid chain length in plants and algae via hydrolysis, but the mechanism was unclear.
Purpose of the Study:
- To elucidate the catalytic mechanism of thioesterases in determining fatty acid chain length.
- To identify structural features responsible for substrate and protein binding.
- To explore engineering thioesterases for targeted fatty acid production.
Main Methods:
- X-ray crystallography at 2.50 Å resolution to determine enzyme structure.
- AlphaFold Multimer modeling to generate a protein complex model.
- Site-directed mutagenesis to assess the impact of residue changes on catalysis and product formation.
Main Results:
- Identified key active-site, substrate-binding, and protein-binding features.
- Proposed a catalytic mechanism involving water as a general base and specific surface residues for acyl carrier protein coordination.
- Demonstrated that altering the binding tunnel restructures substrate specificity.
- Engineered a non-native thioesterase for 95% hydrolysis of C12 fatty acids.
Conclusions:
- The study reveals the molecular basis of thioesterase-mediated fatty acid chain-length determination.
- Structural insights enable rational design of thioesterases for targeted fatty acid production in algae.
- This work provides a foundation for engineering algal lipid biosynthesis for industrial applications.
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