5WRV

Complex structure of human SRP72/SRP68


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.7 Å
  • R-Value Free: 0.189 
  • R-Value Work: 0.164 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Human apo-SRP72 and SRP68/72 complex structures reveal the molecular basis of protein translocation

Gao, Y.Zhang, Q.Lang, Y.Liu, Y.Dong, X.Chen, Z.Tian, W.Tang, J.Wu, W.Tong, Y.Chen, Z.

(2017) J Mol Cell Biol 9: 220-230

  • DOI: 10.1093/jmcb/mjx010
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • The co-translational targeting or insertion of secretory and membrane proteins into the endoplasmic reticulum (ER) is a key biological process mediated by the signal recognition particle (SRP). In eukaryotes, the SRP68-SRP72 (SRP68/72) heterodimer pl ...

    The co-translational targeting or insertion of secretory and membrane proteins into the endoplasmic reticulum (ER) is a key biological process mediated by the signal recognition particle (SRP). In eukaryotes, the SRP68-SRP72 (SRP68/72) heterodimer plays an essential role in protein translocation. However, structural information on the two largest SRP proteins, SRP68 and SRP72, is limited, especially regarding their interaction. Herein, we report the first crystal structures of human apo-SRP72 and the SRP68/72 complex at 2.91Å and 1.7Å resolution, respectively. The SRP68-binding domain of SRP72 contains four atypical tetratricopeptide repeats (TPR) and a flexible C-terminal cap. Apo-SRP72 exists mainly as dimers in solution. To bind to SRP68, the SRP72 homodimer disassociates, and the indispensable C-terminal cap undergoes a pronounced conformational change to assist formation of the SRP68/72 heterodimer. A 23-residue polypeptide of SRP68 is sufficient for tight binding to SRP72 through its unusually hydrophobic and extended surface. Structural, biophysical, and mutagenesis analyses revealed that cancer-associated mutations disrupt the SRP68-SRP72 interaction and their co-localization with ER in mammalian cells. The results highlight the essential role of the SRP68-SRP72 interaction in SRP-mediated protein translocation and provide a structural basis for disease diagnosis, pathophysiology, and drug design.


    Organizational Affiliation

    College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.,Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario M5G 1L7, Canada.,Beijing Advanced Innovation Center for Food Nutrition and Human Health, State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China.,Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Beijing 100093, China.,Structural Genomics Consortium, Toronto, Ontario M5G 1L7, Canada.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Signal recognition particle subunit SRP68
A
106Homo sapiensMutation(s): 3 
Gene Names: SRP68
Find proteins for Q9UHB9 (Homo sapiens)
Go to Gene View: SRP68
Go to UniProtKB:  Q9UHB9
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Signal recognition particle subunit SRP72
B
163Homo sapiensMutation(s): 0 
Gene Names: SRP72
Find proteins for O76094 (Homo sapiens)
Go to Gene View: SRP72
Go to UniProtKB:  O76094
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NA
Query on NA

Download SDF File 
Download CCD File 
B
SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N
 Ligand Interaction
SO4
Query on SO4

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Download CCD File 
B
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
ACT
Query on ACT

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Download CCD File 
A, B
ACETATE ION
C2 H3 O2
QTBSBXVTEAMEQO-UHFFFAOYSA-M
 Ligand Interaction
GOL
Query on GOL

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Download CCD File 
A, B
GLYCEROL
GLYCERIN; PROPANE-1,2,3-TRIOL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.7 Å
  • R-Value Free: 0.189 
  • R-Value Work: 0.164 
  • Space Group: P 63 2 2
Unit Cell:
Length (Å)Angle (°)
a = 120.598α = 90.00
b = 120.598β = 90.00
c = 80.001γ = 120.00
Software Package:
Software NamePurpose
HKL-2000data reduction
REFMACrefinement
HKL-2000data scaling
SHELXphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

  • Deposited Date: 2016-12-04 
  • Released Date: 2017-06-21 
  • Deposition Author(s): Gao, Y., Chen, Z.

Revision History 

  • Version 1.0: 2017-06-21
    Type: Initial release
  • Version 1.1: 2017-07-05
    Type: Database references, Refinement description