Ufmylation is a post-translational modification essential for regulating key cellular processes. A three-enzyme cascade involving E1, E2 and E3 is required for UFM1 attachment to target proteins. How UBA5 (E1) and UFC1 (E2) cooperatively activate and transfer UFM1 is still unclear. Here, we present the crystal structure of UFC1 bound to the C-terminus of UBA5, revealing how UBA5 interacts with UFC1 via a short linear sequence, not observed in other E1-E2 complexes. We find that UBA5 has a region outside the adenylation domain that is dispensable for UFC1 binding but critical for UFM1 transfer. This region moves next to UFC1’s active site Cys and compensates for a missing loop in UFC1, which exists in other E2s and is needed for the transfer. Overall, our findings advance the understanding of UFM1’s conjugation machinery and may serve as a basis for the development of ufmylation inhibitors.
|State||Published - 29 Sep 2021|
Bibliographical noteFunding Information:
We thank the beamline staff of BESSY-II 14.1 and ESRF ID23. This work was supported by the Israel Science Foundation (grant 1383/17) to R.W, (grant 1889/18) to R.R, (grant 717/2017) to O.S.F and (grant 401/18) to M.D, the Israel Cancer Research Fund (grant 3013000281) to R.W and the US-Israel Binational Science Foundation (grant 2015207) to O.S.F.
© 2021, The Author(s).