A nascent secretory protein may traverse the ribosome/endoplasmic reticulum translocase complex as an extended chain.
We have measured the minimum number of residues in a translocating polypeptide required to bridge the distance between the P-site in endoplasmic reticulum-bound ribosomes and the lumenally disposed active site of the oligosaccharyl transferase. The results suggest that a nascent chain may traverse the ribosome/translocase complex in a largely extended conformation, and that hydrophobic stop-transfer segments have a more compact, possibly alpha-helical conformation in the translocase.
Whitley
P
P
Department of Biochemistry, Stockholm University, Sweden.
Nilsson
I M
IM
von Heijne
G
G
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009844:Oligosaccharides / Q000378:metabolism; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D012270:Ribosomes / Q000378:metabolism*
D001426:Bacterial Proteins; D009844:Oligosaccharides