Fig. 2: REEP/Yop1 monomers interact in membranes through TM2.

a Photoreactive Bpa probes were incorporated into Yop1 at the indicated positions of different TMs. The purified protein was irradiated with UV light either in DDM or after reconstitution in liposomes containing S. cerevisiae lipids at a 1:200 molar ratio of protein to lipid. The samples were analyzed by SDS-PAGE and Coomassie-blue staining. The asterisk indicates the position of the cross-linked Yop1F65Bpa dimer. The right panel shows quantification of the intensity of dimer cross-links relative to total protein. b As in a, but with mutants in the APH reconstituted into proteoliposomes. c Quantification of experiments as carried out in b. Data are presented as mean ± the standard deviation (SD) from n = 10 (wt) and n = 3 (I145R, I145K, I145E, ΔAPH) independent experiments. d Dimer formation was tested with purified REEPs from Schizosaccharomyces japonicus (S. jap), Xenopus laevis (X. lae), Thermothelomyces thermophila (T. the) and Thielavia terrestris (T. ter). In each case, a Bpa probe was incorporated at the position of the conserved Phe residue in TM2. The samples were analyzed as in a. The asterisks show the positions of cross-linked dimers.