An Interaction Map Summarizing the Data Obtained from Both Native MS and Cross-Linking MS Analysis
Rpn5, Rpn6, Rpn8, and Rpn9 form a tetrameric structure, in which Rpn8 occupies a central position. The dashed line circling Rpn6 indicates that it is present in substoichiometric amounts. Both Rpn7 and Rpn3 bind to Sem1. Considering the small size of Sem1, it is reasonable to suggest that Rpn3 and Rpn7 are in close proximity. In addition, we could determine that Rpn3 binds to Rpn5. Rpn11 interacts with Rpn3:7 or Rpn5:9; these possible interactions are labeled with a dashed line. No Interactions were determined for Rpn12. Subunits are colored either red, purple, or blue, indicating their increasing exposure within the complex.