Mechanistic insight into TRIP13-catalyzed Mad2 structural transition and spindle checkpoint silencing

• DOI: 10.1038/s41467-017-02012-2
• Publication Date: 2017-11-29T17:36:32Z
• Authors: Melissa L. Brulotte; Byung-Cheon Jeong; Faxiang Li; Bing Li; Eric B. Yu; Qiong Wu; Chad A. Brautigam; Hongtao Yu; Xuelian Luo
• Keywords: Mad2; CDC20; Spindle checkpoint

Abstract The spindle checkpoint maintains genomic stability and prevents aneuploidy. Unattached kinetochores convert the latent open conformer of protein Mad2 (O-Mad2) to active closed (C-Mad2), bound Cdc20. C-Mad2–Cdc20 is incorporated into mitotic complex (MCC), which inhibits anaphase-promoting complex/cyclosome (APC/C). C-Mad2-binding p31 comet ATPase TRIP13 promote MCC disassembly silencing. Here, using nuclear magnetic resonance (NMR) spectroscopy, we show that catalyze conversion C-Mad2 O-Mad2, without disrupting its stably folded core. We determine crystal structure human TRIP13, identify functional residues mediate –Mad2 binding couple ATP hydrolysis local unfolding Mad2. prevent APC/C inhibition by components, but cannot reactivate already MCC. Therefore, TRIP13–p31 intercepts disassembles free not through mediating C-terminal region.