(E) Euc1-SBM constructs show defective Slx5 binding in vivo. Mutations described in (D) were introduced into full-length Euc1 constructs (with or without the K231R mutation) and FLAG IPs were performed as described in (C). WB analysis showed strong Slx5-binding defects for the SBM1/SBM2 and SBM1+2 constructs (top panel, immunoprecipitated Slx5). WBs were probed as in (C). 