Structural basis of dynamic P5CS filaments
- ShanghaiTech University, China
Abstract
The bifunctional enzyme Δ1-pyrroline-5-carboxylate synthase (P5CS) is vital to the synthesis of proline and ornithine, playing an essential role in human health and agriculture. Pathogenic mutations in P5CS gene (ALDH18A1) lead to neurocutaneous syndrome and skin relaxation connective tissue disease in humans, and P5CS deficiency seriously damages the ability to resist adversity in plants. We have recently found that P5CS forms the cytoophidium in vivo and filaments in vitro. However, it is difficult to appreciate the function of P5CS filamentation without precise structures. Using cryo-electron microscopy, here we solve structures of Drosophila full-length P5CS in three states at resolution from 3.1 to 4.3 Å. We observe distinct ligand-binding states and conformational changes for the GK and GPR domains, respectively. Divergent helical filaments are assembled by P5CS tetramers and stabilized by multiple interfaces. Point mutations disturbing those interfaces prevent P5CS filamentation and greatly reduce the enzymatic activity. Our findings reveal that filamentation is crucial for the coordination between the GK and GPR domains, providing structural basis for catalytic function of P5CS filaments.
Data availability
7F5T 7F5U 7F5V 7F5X 7WX3 7WX4 7WXF 7WXG 7WXH 7WXIFigure 5-Source Data 1 in enzyme activity assay, which related to Figure 5D;Validation summary report as Related Manuscript File;Maps and coordinates data as a Supporting Zip Document.
Article and author information
Author details
Funding
Ministry of Science and Technology of the People's Republic of China (2021YFA0804701-4)
- Ji-Long Liu
National Natural Science Foundation of China (31771490)
- Ji-Long Liu
Shanghai Science and Technology Commission (20JC1410500)
- Ji-Long Liu
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2022, Zhong et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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Structural basis of dynamic P5CS filaments
eLife 11:e76107.
https://doi.org/10.7554/eLife.76107
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