2FH5

The Structure of the Mammalian SRP Receptor


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.45 Å
  • R-Value Free: 0.232 
  • R-Value Work: 0.193 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

The structure of the mammalian signal recognition particle (SRP) receptor as prototype for the interaction of small GTPases with Longin domains.

Schlenker, O.Hendricks, A.Sinning, I.Wild, K.

(2006) J.Biol.Chem. 281: 8898-8906

  • DOI: 10.1074/jbc.M512415200

  • PubMed Abstract: 
  • The eukaryotic signal recognition particle (SRP) and its receptor (SR) play a central role in co-translational targeting of secretory and membrane proteins to the endoplasmic reticulum. The SR is a heterodimeric complex assembled by the two GTPases S ...

    The eukaryotic signal recognition particle (SRP) and its receptor (SR) play a central role in co-translational targeting of secretory and membrane proteins to the endoplasmic reticulum. The SR is a heterodimeric complex assembled by the two GTPases SRalpha and SRbeta, which is membrane-anchored. Here we present the 2.45-A structure of mammalian SRbeta in its Mg2+ GTP-bound state in complex with the minimal binding domain of SRalpha termed SRX. SRbeta is a member of the Ras-GTPase superfamily closely related to Arf and Sar1, while SRX belongs to the SNARE-like superfamily with a fold also known as longin domain. SRX binds to the P loop and the switch regions of SRbeta-GTP. The binding mode and structural similarity with other GTPase-effector complexes suggests a co-GAP (GTPase-activating protein) function for SRX. Comparison with the homologous yeast structure and other longin domains reveals a conserved adjustable hydrophobic surface within SRX which is of central importance for the SRbeta-GTP:SRX interface. A helix swap in SRX results in the formation of a dimer in the crystal structure. Based on structural conservation we present the SRbeta-GTP:SRX structure as a prototype for conserved interactions in a variety of GTPase regulated targeting events occurring at endomembranes.


    Organizational Affiliation

    Biochemie-Zentrum der Universit├Ąt Heidelberg (BZH), Im Neuenheimer Feld 328, D-69120 Heidelberg, Germany.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Signal recognition particle receptor alpha subunit
A
185Homo sapiensMutation(s): 0 
Gene Names: SRPRA (SRPR)
Find proteins for P08240 (Homo sapiens)
Go to Gene View: SRPRA
Go to UniProtKB:  P08240
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Signal recognition particle receptor beta subunit
B
214Mus musculusMutation(s): 0 
Gene Names: Srprb
Find proteins for P47758 (Mus musculus)
Go to UniProtKB:  P47758
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GTP
Query on GTP

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

Download SDF File 
Download CCD File 
B
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.45 Å
  • R-Value Free: 0.232 
  • R-Value Work: 0.193 
  • Space Group: I 2 2 2
Unit Cell:
Length (Å)Angle (°)
a = 68.092α = 90.00
b = 118.348β = 90.00
c = 120.413γ = 90.00
Software Package:
Software NamePurpose
CNSrefinement
AMoREphasing
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2006-01-31
    Type: Initial release
  • Version 1.1: 2008-05-01
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance