5WRW

Structure of human apo-SRP72


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.91 Å
  • R-Value Free: 0.266 
  • R-Value Work: 0.232 
  • R-Value Observed: 0.234 

Starting Model: experimental
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wwPDB Validation   3D Report Full Report


This is version 1.2 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: https://doi.org/10.1093/jmcb/mjx010
  • Primary Citation of Related Structures:  
    5WRV, 5WRW

  • 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 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

    Beijing Advanced Innovation Center for Food Nutrition and Human Health, State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Signal recognition particle subunit SRP72
A, B, C, D, E
A, B, C, D, E, F
163Homo sapiensMutation(s): 0 
Gene Names: SRP72
UniProt & NIH Common Fund Data Resources
Find proteins for O76094 (Homo sapiens)
Explore O76094 
Go to UniProtKB:  O76094
PHAROS:  O76094
GTEx:  ENSG00000174780 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupO76094
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.91 Å
  • R-Value Free: 0.266 
  • R-Value Work: 0.232 
  • R-Value Observed: 0.234 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 83.435α = 90
b = 123.715β = 90
c = 150.723γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
HKL-2000data reduction
HKL-2000data scaling
MOLREPphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2017-06-21
    Type: Initial release
  • Version 1.1: 2017-07-05
    Changes: Database references
  • Version 1.2: 2023-11-08
    Changes: Data collection, Database references, Refinement description