B Wild-type FICD forms homomeric complexes in vivo. Immunoblots of orthogonally-tagged wild-type and Leu258Asp mutant FICD in the input cell lysate and following recovery by pull-down with streptavidin (recognising the AviTag) or anti-FLAG antibody. Proteins were detected with fluorescently-labelled streptavidin (StrepIR800) or FLAG antibody. Data representative of three independent experiments are shown. 