Distinct modes of signal recognition particle interaction with the ribosome.
Signal recognition particle (SRP), together with its receptor (SR), mediates the targeting of ribosome-nascent chain complexes to the endoplasmic reticulum. Using protein cross-linking, we detected distinct modes in the binding of SRP to the ribosome. During signal peptide recognition, SRP54 is positioned at the exit site close to ribosomal proteins L23a and L35. When SRP54 contacts SR, SRP54 is rearranged such that it is no longer close to L23a. This repositioning may allow the translocon to dock with the ribosome, leading to insertion of the signal peptide into the translocation channel.
Pool
Martin R
MR
Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), D-69120 Heidelberg, Germany. mrp@zmbh.uni-heidelberg.de
Stumm
Joachim
J
Fulga
Tudor A
TA
Sinning
Irmgard
I
Dobberstein
Bernhard
B
D000818:Animals; D002499:Centrifugation, Density Gradient; D003432:Cross-Linking Reagents; D004285:Dogs; D006153:Guanosine Diphosphate / Q000378:metabolism / Q000494:pharmacology; D006160:Guanosine Triphosphate / Q000378:metabolism; D006165:Guanylyl Imidodiphosphate / Q000378:metabolism / Q000494:pharmacology; D008958:Models, Molecular; D010940:Plant Proteins / Q000737:chemistry / Q000378:metabolism; D011233:Precipitin Tests; D011388:Prolactin / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D011498:Protein Precursors / Q000235:genetics / Q000378:metabolism; D021382:Protein Sorting Signals; D021381:Protein Transport; D018160:Receptors, Cytoplasmic and Nuclear / Q000737:chemistry / Q000378:metabolism; D018000:Receptors, Peptide / Q000737:chemistry / Q000378:metabolism; D012269:Ribosomal Proteins / Q000737:chemistry / Q000378:metabolism*; D012270:Ribosomes / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D018271:Signal Recognition Particle / Q000737:chemistry / Q000378:metabolism*; D013388:Succinimides
D003432:Cross-Linking Reagents; D010940:Plant Proteins; D011498:Protein Precursors; D021382:Protein Sorting Signals; C489280:RPL35A protein, S cerevisiae; D018160:Receptors, Cytoplasmic and Nuclear; D018000:Receptors, Peptide; D012269:Ribosomal Proteins; C069268:SRP54 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D018271:Signal Recognition Particle; D013388:Succinimides; C036318:signal peptide receptor; D006153:Guanosine Diphosphate; D006165:Guanylyl Imidodiphosphate; C017671:preprolactin; D006160:Guanosine Triphosphate; D011388:Prolactin; C019358:disuccinimidyl suberate