Fig. 2.

Identification of tail-anchor-specific cytosolic factors. (A) Comparable amounts of opsin epitope-tagged versions (OPG) of a Sec61β variant lacking the transmembrane domain (−TMD), full-length Sec61β and RAMP4 (supplementary material Fig. S1A) were immobilised on UltraLink Biosupport, incubated with rabbit reticulocyte lysate and binding partners eluted with 0.1% (v/v) Triton X-100 after extensive washing. Following SDS-PAGE and Coomassie Blue staining, components strongly enriched in lanes 2 and 3 were further characterised. Relevant proteins successfully identified by mass spectrometry are shown (*, **), other candidates (?) remain uncharacterised. (B) Eluted material was analysed by immunoblotting for specific components, as indicated.