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Inner Mitochondrial Membrane Sensitivity to Na+ Reveals Partially Segmented Functional CoQ Pools
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Pterocarpan synthase (PTS) structures suggest a common quinone methide-stabilizing function in dirigent proteins and
Qingyan Meng1, Syed G A Moinuddin1, Sung-Jin Kim1
1Institute of Biological Chemistry, Washington State University, Pullman, Washington, USA.
The Journal of Biological Chemistry
|June 23, 2020
Summary
Dirigent proteins (DPs) form complex plant phenolics. We determined the 3D structures of two DPs, revealing their roles in pterocarpan biosynthesis and suggesting a common mechanism for DP evolution.
Area of Science:
- Biochemistry and Molecular Biology
- Plant Science and Evolution
Background:
- Dirigent proteins (DPs) are crucial for synthesizing diverse plant phenolics, with many families awaiting functional characterization.
- DPs emerged during the plant aquatic-to-land transition, indicating their evolutionary significance.
Purpose of the Study:
- To elucidate the 3D structures of two pterocarpan-forming proteins with dirigent-like domains.
- To understand the biochemical mechanisms underlying DP function and their evolutionary diversification.
Main Methods:
- Determined the 3D structures of two pterocarpan-forming proteins.
- Analyzed stereospecific conversion of isoflavonoid precursors to pterocarpans.
- Compared structures with DP orthologs involved in lignan and aromatic terpenoid synthesis.
Main Results:
- Elucidated the 3D structures of two proteins catalyzing stereospecific conversion of precursors to (-)- and (+)-medicarpin.
- Identified a common biochemical mechanism involving stabilization of quinone methide intermediates across different DP families.
- Provided structural basis for DP functional diversification during land plant evolution.
Conclusions:
- The findings offer key insights into the evolutionary appearance and diversification of DPs.
- Proposed biochemical mechanisms provide a framework for identifying novel physiological roles of DPs and related proteins.
Keywords:
crystallographydimerizationdirigent proteindockinglignansligninsplant biochemistryplant defensepterocarpansquinone methidesMore Related Videos
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