a, Superimposition of the structures of V2c–SVBP (colored as in Fig. 1a) and V2–SVBP (colored in wheat) in cartoon representation. The rmsd of the two superimposed structures is 0.29 Å. The comparison reveals that the structures of V2c and full-length V2 are almost the same, and that the N- and C-terminal flanking regions of V2 are disordered. b, Superimposition of the structures of V2c–SVBP (colored as in Fig. 1a) and V1c–SVBP (colored in wheat) in cartoon representation. Though full-length SVBP was used for all the structure determinations, it should be noted that the α-helix of SVBP observed in the V1c–SVBP structure is two turns shorter as compared to the one observed in the V2c–SVBP structure. The rmsd of the two superimposed structures is 0.80 Å. The comparison reveals that the structures of V2c and V1c are very similar. c, Immunoblot of tubulin detyrosination assays performed in HEK293T cells with different V2 variants, including wild-type V2 and V2c and active site V2 mutants. Plasmids encoding wild type or mutated V2-eGFP and wild type SVBP-myc-Flag were cotransfected into cells. Antibodies specific to detyrosinated tubulin are used to assess detyrosinase activity. Antibodies against GAPDH, eGFP (V2 and variants), and Flag (SVBP) reveal the amounts of protein in the extract. Non-transfected cells reveal the endogenous levels of detyrosinated tubulin. (+) refers to wild type V2 or SVBP proteins. Immunoblots are representative of results obtained from at least three independent experiments (see Supplementary Fig. 2a). Uncropped images are shown in Supplementary Data Set 1.