9MQF

Chloroplast acyl-ACP thioesterase from Chlamydomonas reinhardtii

Summary for 9MQF

• Entry DOI: 10.2210/pdb9mqf/pdb
• Descriptor: Acyl-[acyl-carrier-protein] hydrolase (2 entities in total)
• Functional Keywords: thioesterase, fatty acid biosynthesis, chloroplast, hydrolase
• Biological source: Chlamydomonas reinhardtii
• Total number of polymer chains: 1
• Total formula weight: 39000.77

Authors

Chen, J.A.,Suo, Y.,Mayfield, S.P.,Burkart, M.D. (deposition date: 2025-01-02, release date: 2025-08-13, Last modification date: 2025-08-27)

Primary citation

Chen, J.A.,Suo, Y.,Mayfield, S.P.,Burkart, M.D.
Structural Characterization of an Endogenous Algal Acyl-ACP Thioesterase.
Biochemistry, 64:3508-3514, 2025

PubMed Abstract: Fatty acids of specific chain lengths offer precursors for high-value renewable energy and fine chemicals industries. In plants and algae, the fatty acid chain length is determined by thioesterase-mediated hydrolysis of fatty acids from acyl carrier proteins through a hitherto unclear mechanism. Herein, a 2.50 Å resolution X-ray crystallography structure and an AlphaFold Multimer-generated model were used to identify active-site, substrate-binding, and protein-binding features contributing to catalysis. Coupled with mutational studies to determine impacts on product formation, we propose a catalytic mechanism involving water as a general base with surface residues specific to coordinating acyl carrier protein alignment. Binding tunnel restructuring altered substrate specificity of the thioesterase, and introduction of a non-native thioesterase with matching protein interface gave 95% hydrolysis of C12 fatty acids, offering new approaches for algae fatty acid biosynthetic design.

PubMed: 40768417
DOI: 10.1021/acs.biochem.5c00088

Experimental method

X-RAY DIFFRACTION (2.5 Å)