Fig. 2: OST-A is recruited during translocation of long segments through open Sec61.
From: Global analysis of translocon remodeling during protein synthesis at the ER
a, The OST-A interaction profile for Neo1. The mean enrichment (line) and range (shaded) for n = 3 replicates are indicated. A diagram of Neo1 is shown above the plot, indicating the signal peptide (gray), lumenal (blue) and cytosolic (yellow) segments, and the single transmembrane domain (TMD) (red). N-glycosylation (N-glyc) acceptor sequences are indicated below by vertical gray lines. This convention is used throughout the manuscript. b, Metagene plots of OST-A recruitment to SP-only, type I and type II single-pass proteins, aligned on the end of the indicated feature. The number of sequences (N), median and interquartile range are indicated. Only proteins with lumenal segments ≥300 residues are included in the analysis. c, The cumulative fraction of proteins whose first N-glycosylation acceptor site (N-X-T/S, X ≠ P) is exposed in the lumen at the point of near-maximal OST-A recruitment (defined as 135 residues past the end of the SP or TMD). d, Enrichment scores for SP-only, type I and type II single-pass proteins with or without a lumenal N-glycosylation acceptor site. The number of sequences (N), median and interquartile range are indicated. Only proteins with lumenal segments ≥150 residues are included. e, Metagene plots of OST-A departure, as in b, aligned on the end of the protein (SP-only and type II) or TMD (type I). Only type I proteins with lumenal C-tails ≥100 were included in the analysis. f, OST-A arrival and departure during synthesis of a type I single-pass membrane protein at the ribosome (ribo.)-translocon complex.
