In: The Journal of Biological Chemistry, 268 (1993), Nr. 35. pp. 26746-2671
A chemically charged amber suppressor tRNA was used to introduce the photoactivatable amino acid (Tmd)Phe at a selected position within the signal sequence of the secretory protein preprolactin. This allowed the interactions of the NH -terminal, the central, and the COOH-terminal regions of the signal sequence to be investigated during insertion into the membrane of the endoplasmic reticulum (ER). We found that different regions of the nascent chains were photocross-linked to different ER proteins. The TRAM protein (translocating chain-associating membrane protein) contacts the NHz-terminal region of the signal sequence while the mammalian Sec6lp contacts the hydrophobic core of the signal sequence and regions COOH-terminal of this. These results suggest that the ER translocation complex is composed of heterologous protein subunits which contadcti stinct regions of nascent polypeptides during their membrane insertion.
|Journal or Publication Title:||The Journal of Biological Chemistry|
|Date Deposited:||17. Jul 2008 17:10|
|Page Range:||pp. 26746-2671|
|Faculties / Institutes:||Service facilities > Center for Molecular Biology Heidelberg|
|Subjects:||570 Life sciences|
|Schriftenreihe ID:||Works by Bernhard Dobberstein|