1RY1: Structure of the Signal Recognition Particle Interacting With the Elongation-arrested Ribosome

Citation:
Abstract
Cotranslational translocation of proteins across or into membranes is a vital process in all kingdoms of life. It requires that the translating ribosome be targeted to the membrane by the signal recognition particle (SRP), an evolutionarily conserved ribonucleoprotein particle. SRP recognizes signal sequences of nascent protein chains emerging from the ribosome. Subsequent binding of SRP leads to a pause in peptide elongation and to the ribosome docking to the membrane-bound SRP receptor. Here we present the structure of a targeting complex consisting of mammalian SRP bound to an active 80S ribosome carrying a signal sequence. This structure, solved to 12 A by cryo-electron microscopy, enables us to generate a molecular model of SRP in its functional conformation. The model shows how the S domain of SRP contacts the large ribosomal subunit at the nascent chain exit site to bind the signal sequence, and that the Alu domain reaches into the elongation-factor-binding site of the ribosome, explaining its elongation arrest activity.
PDB ID: 1RY1Download
MMDB ID: 106053
PDB Deposition Date: 2003/12/19
Updated in MMDB: 2012/12 
Experimental Method:
electron microscopy
Resolution: 12  Å
Source Organism:
synthetic construct
Similar Structures:
Biological Unit for 1RY1: tetradecameric; determined by author
Molecular Components in 1RY1
Label Count Molecule
Proteins (6 molecules)
1
Protein (Signal Recognition Particle 9 KDA Protein)
(Gene: SRP9)
Molecule annotation
1
Protein (Signal Recognition Particle 14 KDA Protein)
(Gene: SRP14)
Molecule annotation
1
Protein (Signal Recognition Particle 19 KDA Protein)
(Gene: SRP19)
Molecule annotation
1
Signal Recognition Particle Protein
Molecule annotation
1
Signal Recognition Particle 54 KDA Protein
(Gene: Srp54a)
Molecule annotation
1
Rhodopsin
Molecule annotation
Nucleotides(8 molecules)
1
ALU Domain (Rna Fragments)
Molecule annotation
1
ALU Domain (Srp9, Srp14 + Rna)
Molecule annotation
1
Fragment of 7S RNA
Molecule annotation
1
RNA (31-mer)
Molecule annotation
1
RNA (5'- R(p*gp*up*up*cp*up*gp*gp*gp*cp*up*gp*up*ap*gp*up*gp*cp*gp*c P*up*ap*up*gp*c)-3')
Molecule annotation
1
RNA (5'- R(*cp*ap*ap*up*ap*gp*cp*cp*ap*cp*up*gp*cp*ap*cp*up*cp*cp*ap *g)-3')
Molecule annotation
1
RNA (5'-r(p*cp*gp*ap*up*cp*gp*gp*gp*up*gp*up*c)- 3')
Molecule annotation
1
RNA (5'-r(p*ap*up*cp*gp*cp*gp*cp*cp*up*gp*up*g)- 3')
Molecule annotation
* Click molecule labels to explore molecular sequence information.

Citing MMDB
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