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Structural basis for UFM1 transfer from UBA5 to UFC1
Manoj Kumar1, Prasanth Padala1,2, Jamal Fahoum1
1Department of Biochemistry and Molecular Biology, The Institute for Medical Research Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, 91120, Israel.
Nature Communications
|September 30, 2021
Summary
This study reveals the structural basis for UFM1 (ubiquitin fold modifier 1) conjugation by UBA5 (E1 enzyme) and UFC1 (E2 enzyme). Findings clarify how UBA5 facilitates UFM1 transfer, aiding ufmylation pathway research.
Area of Science:
- Biochemistry
- Molecular Biology
- Structural Biology
Background:
- Ufmylation is a crucial post-translational modification regulating cellular functions.
- A three-enzyme cascade (E1, E2, E3) mediates UFM1 attachment to substrates.
- The precise mechanism of UFM1 activation and transfer by UBA5 (E1) and UFC1 (E2) remains elusive.
Purpose of the Study:
- To elucidate the structural mechanisms underlying UFM1 conjugation by UBA5 and UFC1.
- To understand the cooperative activation and UFM1 transfer process.
- To provide insights for developing ufmylation inhibitors.
Main Methods:
- X-ray crystallography to determine the structure of UFC1 bound to UBA5.
- Biochemical assays to assess UFM1 transfer efficiency.
Main Results:
- The crystal structure reveals a unique interaction between UBA5 and UFC1 via a short linear motif.
- A region of UBA5, outside its adenylation domain, is critical for UFM1 transfer, not just binding.
- This UBA5 region compensates for a loop absent in UFC1, facilitating UFM1 transfer to the active site cysteine.
Conclusions:
- The study clarifies the UBA5-UFC1 interaction and the mechanism of UFM1 transfer.
- Identified a novel mechanism involving UBA5 in facilitating E2 activity.
- Findings offer a structural basis for understanding the ufmylation machinery and developing targeted inhibitors.
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