Unique peptides from identified proteins in the paired mass spectrometry analysis are shown in the columns to the left, mascot scores are shown in the columns to the right. TUBA1B: pull-down with tagged wild-type α-tubulin; P263T and R402H: pull-downs with the respective tagged mutant α-tubulins; b: bead fraction; a: fraction released from beads after cleavage with Sumo* protease.