In: The EMBO Journal, 14 (1995), Nr. 22. pp. 5485-5493.
Translocation of proteins across the endoplasmic reticulum membrane is initiated by the signal recognition particle (SRP), a cytoplasmic ribonucleoprotein complex consisting of a 7S RNA and six polypeptides. To investigate the functions of the SRP components, we have tested the activities of several SRP subparticles. We show that the SRP GTPase (SRP54) alone binds a signal sequence and discriminates it from a non-signal sequence. Although SRP54 alone is unable to promote translocation, SRP54 in a complex with SRP RNA is both necessary and sufficient to promote translocation of an elongation-arrested nascent protein in a GTPregulated manner. For co-translational translocation, additional SRP components are required. We discuss the implications of our results for the function of the Escherichia coli SRP which is homologous to the SRP54/SRP-RNA complex.
|Journal or Publication Title:||The EMBO Journal|
|Page Range:||pp. 5485-5493|
|Faculties / Institutes:||Service facilities > Center for Molecular Biology Heidelberg|
|Subjects:||570 Life sciences|
|Uncontrolled Keywords:||endoplasmic reticulum , protein translocation , signal recognition particle (SRP) , signal sequence recognition , 4.5S RNA|
|Schriftenreihe ID:||Works by Bernhard Dobberstein|