IM-MS of a Circadian Clock Protein Complex Reveals a Ligand-Dependent Conformational Switch

摘要

Native mass spectrometry enabled the discovery of an FAD-dependent conformational change in a mammalian cryptochrome complex, even though interactions between FAD and Cry2 protein appear to be very weak. Interestingly, a truncated form of the complex (-3 kDa) only adopts compact structures, suggesting that the truncation is critical for the additional conformation observed for the full-length complex. Tandem MS, IM, and computational modeling provide insights into the location of the truncation and the associated structures.