Determination of the distance between the oligosaccharyltransferase active site and the endoplasmic reticulum membrane.
By in vitro transcription/translation of model proteins in the presence of dog pancreas microsomes, we have measured the minimum distance of an acceptor site from the lumenal end of a transmembrane segment required for N-linked glycosylation, both when the acceptor site is placed N- and C-terminally to the membrane anchor. We observe a sharp threshold at a distance of 12-14 residues, suggesting that the oligosaccharyltransferase active site is 30-40 A above the membrane and is oriented roughly parallel to the membrane surface.
Nilsson
I M
IM
Department of Molecular Biology, Karolinska Institute Center for Structural Biochemistry, NOVUM, Huddinge, Sweden.
von Heijne
G
G
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D004247:DNA; D004285:Dogs; D010450:Endopeptidases / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology; D006031:Glycosylation; D006602:Hexosyltransferases; D007425:Intracellular Membranes / Q000378:metabolism; D008565:Membrane Proteins; D008861:Microsomes / Q000201:enzymology; D008969:Molecular Sequence Data; D010179:Pancreas / Q000201:enzymology; D011487:Protein Conformation; D012697:Serine Endopeptidases; D014166:Transferases / Q000737:chemistry / Q000378:metabolism*
D008565:Membrane Proteins; D004247:DNA; D014166:Transferases; D006602:Hexosyltransferases; C025620:dolichyl-diphosphooligosaccharide - protein glycotransferase; D010450:Endopeptidases; D012697:Serine Endopeptidases; C026515:type I signal peptidase