@article {Onoda2022.06.16.496385, author = {Hiroki Onoda and Amika Kikuchi and Kosuke Yamaguchi and Satomi Kori and Shun Matsuzawa and Yoshie Chiba and Shota Tanimoto and Sae Yoshimi and Hiroki Sato and Atsushi Yamagata and Mikako Shirouzu and Naruhiko Adachi and Jafar Sharif and Haruhiko Koseki and Atsuya Nishiyama and Makoto Nakanishi and Pierre-Antoine Defossez and Kyohei Arita}, title = {Structural basis for activation of DNMT1}, elocation-id = {2022.06.16.496385}, year = {2022}, doi = {10.1101/2022.06.16.496385}, publisher = {Cold Spring Harbor Laboratory}, abstract = {DNMT1 is an essential enzyme that maintains genomic DNA methylation, and its function is regulated by mechanisms that are not yet fully understood. Here, we report the cryo-EM structure of nearly full-length human DNMT1 bound to its two natural activators: hemimethylated DNA and ubiquitinated histone H3. We find that a hitherto unstudied linker, between the RFTS and CXXC domains, plays a key role for activation. It contains a conserved α-helix which engages a crucial {\textquotedblleft}Toggle{\textquotedblright} pocket, displacing a previously described inhibitory linker, and allowing the DNA recognition helix to spring into the active conformation. This is accompanied by large-scale reorganization of the inhibitory RFTS and CXXC domains, allowing the enzyme to gain full activity. Our results therefore provide a mechanistic basis for the activation of DNMT1, with consequences for basic research and drug design.Competing Interest StatementThe authors have declared no competing interest.}, URL = {https://www.biorxiv.org/content/early/2022/06/17/2022.06.16.496385}, eprint = {https://www.biorxiv.org/content/early/2022/06/17/2022.06.16.496385.full.pdf}, journal = {bioRxiv} }