Cryo-EM structures of S-OPA1 reveal its interactions with membrane and changes upon nucleotide binding
| Title: | Cryo-EM structures of S-OPA1 reveal its interactions with membrane and changes upon nucleotide binding |
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| Authors: | Danyang Zhang, Yan Zhang, Jun Ma, Chunmei Zhu, Tongxin Niu, Wenbo Chen, Xiaoyun Pang, Yujia Zhai, Fei Sun |
| Source: | eLife, Vol 9 (2020) |
| Publisher Information: | eLife Sciences Publications Ltd, 2020. |
| Publication Year: | 2020 |
| Collection: | LCC:Medicine LCC:Science LCC:Biology (General) |
| Subject Terms: | cryo-electron microscopy, conformational change, mitochondrial fusion, membrane tubulation, OPA1, Medicine, Science, Biology (General), QH301-705.5 |
| More Details: | Mammalian mitochondrial inner membrane fusion is mediated by optic atrophy 1 (OPA1). Under physiological conditions, OPA1 undergoes proteolytic processing to form a membrane-anchored long isoform (L-OPA1) and a soluble short isoform (S-OPA1). A combination of L-OPA1 and S-OPA1 is essential for efficient membrane fusion; however, the relevant mechanism is not well understood. In this study, we investigate the cryo-electron microscopic structures of S-OPA1–coated liposomes in nucleotide-free and GTPγS-bound states. S-OPA1 exhibits a general dynamin-like structure and can assemble onto membranes in a helical array with a dimer building block. We reveal that hydrophobic residues in its extended membrane-binding domain are critical for its tubulation activity. The binding of GTPγS triggers a conformational change and results in a rearrangement of the helical lattice and tube expansion similar to that of S-Mgm1. These observations indicate that S-OPA1 adopts a dynamin-like power stroke membrane remodeling mechanism during mitochondrial inner membrane fusion. |
| Document Type: | article |
| File Description: | electronic resource |
| Language: | English |
| ISSN: | 2050-084X |
| Relation: | https://elifesciences.org/articles/50294; https://doaj.org/toc/2050-084X |
| DOI: | 10.7554/eLife.50294 |
| Access URL: | https://doaj.org/article/eadd3d0efa0f4127a510dff72fab2be0 |
| Accession Number: | edsdoj.3d0efa0f4127a510dff72fab2be0 |
| Database: | Directory of Open Access Journals |
| ISSN: | 2050084X |
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| DOI: | 10.7554/eLife.50294 |
| Published in: | eLife |
| Language: | English |