Fig. 3: Molecular interactions between the lumenal side of TRAP and the Sec translocon.

a, Sequence alignment of TRAPα in eukaryotes. Loop that potentially contacts the Sec translocon is marked. Hydrophobic residues located within the cradle that were mutated are indicated with a red dot above the sequence. b, Closeup of the contact region between TRAP and the Sec translocon. Region of the closeup is marked with a dashed red box on a schematic in c. Loop of TRAPα that potentially contacts Sec translocon is indicated and colored light brown. Translocon channel plug is labeled and shown in dark green. c, Schematic of the Sec translocon and TRAP complex bound to the ribosome. Dashed red box indicates the closeup region shown in b. Dashed blue line indicates the plane of view used in e. Ribosome, Sec translocon and TRAP cradle lumenal domain are labeled. d, Fluorescence microscope images of C. elegans TRAPα KO worms expressing hsp-4p::GFP and indicated TRAPα variants. Analysis was performed on day 1 of adulthood. Scale bar, 0.2 mm. e, TRAP complex lumenal domain is shown as surface representation with proteins colored individually. Each TRAP protein that contributes to the lumenal domain is labeled. Sec translocon channel pore exit is indicated with a black dashed circle. Residues that were mutated are indicated in red. f, Fluorescence microscope images of C. elegans TRAPα KO worms expressing hsp-4p::GFP and complemented with either wild-type TRAPα or the cradle mutant. Scale bar, 0.2 mm. g, TRAPα KO worms expressing the indicated TRAPα variants and carrying the daf-2(e1368) mutation were grown at 24.5 °C for 2 days. Diagram shows percentage of worms in the dauer state. Data are presented as mean values ± s.d. n = 3 independent experiments. Red circles indicate individual datapoints.