RNA-mediated interaction between the peptide-binding and GTPase domains of the signal recognition particle

Nat Struct Mol Biol. 2005 Dec;12(12):1116-22. doi: 10.1038/nsmb1025. Epub 2005 Nov 20.


The signal recognition particle (SRP) targets nascent proteins to cellular membranes for insertion or secretion by recognizing polypeptides containing an N-terminal signal sequence as they emerge from the ribosome. GTP-dependent binding of SRP to its receptor protein leads to controlled release of the nascent chain into a membrane-spanning translocon pore. Here we show that the association of the SRP with its receptor triggers a marked conformational change in the complex, localizing the SRP RNA and the adjacent signal peptide-binding site at the SRP-receptor heterodimer interface. The orientation of the RNA suggests how peptide binding and GTP hydrolysis can be coupled through direct structural contact during cycles of SRP-directed protein translocation.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Bacterial Proteins / chemistry*
  • Bacterial Proteins / metabolism
  • Binding Sites
  • Dimerization
  • Escherichia coli Proteins / chemistry*
  • Escherichia coli Proteins / metabolism
  • GTP Phosphohydrolases / chemistry*
  • GTP Phosphohydrolases / metabolism
  • Guanosine Triphosphate / metabolism
  • Hydrolysis
  • Peptides / metabolism
  • Protein Conformation
  • Protein Structure, Tertiary
  • RNA, Bacterial
  • RNA, Ribosomal / chemistry*
  • RNA, Ribosomal / metabolism
  • Receptors, Cytoplasmic and Nuclear / chemistry*
  • Receptors, Cytoplasmic and Nuclear / metabolism
  • Receptors, Peptide / chemistry*
  • Receptors, Peptide / metabolism
  • Signal Recognition Particle / chemistry*
  • Signal Recognition Particle / metabolism


  • 4.5S RNA
  • Bacterial Proteins
  • Escherichia coli Proteins
  • Ffh protein, E coli
  • FtsY protein, Bacteria
  • Peptides
  • RNA, Bacterial
  • RNA, Ribosomal
  • Receptors, Cytoplasmic and Nuclear
  • Receptors, Peptide
  • Signal Recognition Particle
  • signal peptide receptor
  • Guanosine Triphosphate
  • GTP Phosphohydrolases

Associated data

  • PDB/1DUL
  • PDB/1QZW
  • PDB/1RJ9
  • PDB/2FFH