Figure 2.

Domain structural models of the components of the BBS2-7-9 complex. A, workflow for the XL-MS experiments. The purified BBS2-7-9 complex was cross-linked and digested with proteases. Cross-linked peptides were enriched and analyzed by LC-MS/MS. Cross-links were identified using the xQuest and pLink search engines. B, models of the domains of BBS2-7-9 complex components were created in I-TASSER except for the BBS9 β-propeller domain, which was from an X-ray crystal structure (PDB 4YD8). Intra-domain cross-links were mapped onto the structures. C, euclidean Cα distance distribution of the lysine cross-links based on the domain structural models. All but one cross-link (orange bar) fit inside the expected distance constraints of 35 Å for DSS, 31 Å for DSG, and 33 Å for Leiker.