1NRJ

Signal Recognition Particle Receptor Beta-Subunit in Complex with the SRX Domain from the Alpha-Subunit


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.229 
  • R-Value Work: 0.194 
  • R-Value Observed: 0.196 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Structural Basis for the Function of the beta Subunit of the Eukaryotic Signal Recognition Particle Receptor

Schwartz, T.Blobel, G.

(2003) Cell 112: 793-803

  • DOI: 10.1016/s0092-8674(03)00161-2
  • Primary Citation of Related Structures:  
    1NRJ

  • PubMed Abstract: 
  • Protein translocation across and insertion into membranes is a process essential to all life forms. In higher eukaryotes, this process is initiated by targeting the translating ribosome to the endoplasmic reticulum via the signal recognition particle ...

    Protein translocation across and insertion into membranes is a process essential to all life forms. In higher eukaryotes, this process is initiated by targeting the translating ribosome to the endoplasmic reticulum via the signal recognition particle (SRP) and its membrane-associated heterodimeric receptor (SR). This targeting step is regulated by three G proteins, SRP54, SR alpha, and SR beta, which act in concert. Little is known about the regulatory role of SR beta. Here, we present the 1.7 A crystal structure of the SR beta-GTP subunit in complex with the interaction domain of SR alpha. Strikingly, the binding interface overlaps largely with the switch 1 region of SR beta. This finding, together with additional biochemical data, shows that the eukaryotic SR is a conditional and not an obligate heterodimer. The results suggest that the GTP/GDP switch cycle of SR beta functions as a regulatory switch for the receptor dimerization. We discuss the implications for the translocation pathway.


    Organizational Affiliation

    Howard Hughes Medical Institute, Laboratory of Cell Biology, The Rockefeller University, 1230 York Avenue, New York, NY 10021, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Signal recognition particle receptor alpha subunit homologA158Saccharomyces cerevisiaeMutation(s): 0 
Gene Names: SRP101
Find proteins for P32916 (Saccharomyces cerevisiae (strain ATCC 204508 / S288c))
Explore P32916 
Go to UniProtKB:  P32916
Protein Feature View
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Signal recognition particle receptor beta subunitB218Saccharomyces cerevisiaeMutation(s): 0 
Gene Names: SRP102
Find proteins for P36057 (Saccharomyces cerevisiae (strain ATCC 204508 / S288c))
Explore P36057 
Go to UniProtKB:  P36057
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GTP
Query on GTP

Download CCD File 
B
GUANOSINE-5'-TRIPHOSPHATE
C10 H16 N5 O14 P3
XKMLYUALXHKNFT-UUOKFMHZSA-N
 Ligand Interaction
EDO
Query on EDO

Download CCD File 
B
1,2-ETHANEDIOL
C2 H6 O2
LYCAIKOWRPUZTN-UHFFFAOYSA-N
 Ligand Interaction
MG
Query on MG

Download CCD File 
B
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
GTPKd:  38   nM  Binding MOAD
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.229 
  • R-Value Work: 0.194 
  • R-Value Observed: 0.196 
  • Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 78.2α = 90
b = 123.7β = 90
c = 48.8γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
HKL-2000data reduction
SCALEPACKdata scaling
SnBphasing
SHARPphasing
DMphasing

Structure Validation

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Entry History 

Deposition Data

  • Deposited Date: 2003-01-24 
  • Released Date: 2003-03-25 
  • Deposition Author(s): Schwartz, T.

Revision History 

  • Version 1.0: 2003-03-25
    Type: Initial release
  • Version 1.1: 2008-04-29
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2017-10-11
    Changes: Refinement description