Deciphering the interaction between TopBP1 and GINS using crosslinking mass spectrometry

Recombinant TopBP1 and GINS were cross linked using the MS non-cleavable crosslinker BS3. Crosslinked proteins were then subsequently either digested directly using the SP3 strategy or first seperated on SDS-PAGE and then in-gel digested. cross-linked peptides were identified by LC-MS. The information from this experiment was used to refine cryo EM structures.