3GN8

X-ray Crystal Structure of AncGR2 in Complex with Dexamethasone


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.255 
  • R-Value Work: 0.196 
  • R-Value Observed: 0.199 

Starting Model: experimental
View more details

wwPDB Validation   3D Report Full Report


Ligand Structure Quality Assessment 


This is version 1.2 of the entry. See complete history


Literature

An epistatic ratchet constrains the direction of glucocorticoid receptor evolution

Bridgham, J.T.Ortlund, E.A.Thornton, J.W.

(2009) Nature 461: 515-519

  • DOI: https://doi.org/10.1038/nature08249
  • Primary Citation of Related Structures:  
    3GN8

  • PubMed Abstract: 

    The extent to which evolution is reversible has long fascinated biologists. Most previous work on the reversibility of morphological and life-history evolution has been indecisive, because of uncertainty and bias in the methods used to infer ancestral states for such characters. Further, despite theoretical work on the factors that could contribute to irreversibility, there is little empirical evidence on its causes, because sufficient understanding of the mechanistic basis for the evolution of new or ancestral phenotypes is seldom available. By studying the reversibility of evolutionary changes in protein structure and function, these limitations can be overcome. Here we show, using the evolution of hormone specificity in the vertebrate glucocorticoid receptor as a case-study, that the evolutionary path by which this protein acquired its new function soon became inaccessible to reverse exploration. Using ancestral gene reconstruction, protein engineering and X-ray crystallography, we demonstrate that five subsequent 'restrictive' mutations, which optimized the new specificity of the glucocorticoid receptor, also destabilized elements of the protein structure that were required to support the ancestral conformation. Unless these ratchet-like epistatic substitutions are restored to their ancestral states, reversing the key function-switching mutations yields a non-functional protein. Reversing the restrictive substitutions first, however, does nothing to enhance the ancestral function. Our findings indicate that even if selection for the ancestral function were imposed, direct reversal would be extremely unlikely, suggesting an important role for historical contingency in protein evolution.


  • Organizational Affiliation

    Center for Ecology and Evolutionary Biology, University of Oregon, Eugene, Oregon 97403, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Glucocorticoid receptor 2
A, B
249Homo sapiensMutation(s): 0 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
Sequence Annotations
Expand
  • Reference Sequence

Find similar proteins by:  Sequence   |   3D Structure  

Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
Nuclear receptor coactivator 2C,
D [auth E]
21N/AMutation(s): 0 
UniProt & NIH Common Fund Data Resources
Find proteins for Q15596 (Homo sapiens)
Explore Q15596 
Go to UniProtKB:  Q15596
PHAROS:  Q15596
GTEx:  ENSG00000140396 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ15596
Sequence Annotations
Expand
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.255 
  • R-Value Work: 0.196 
  • R-Value Observed: 0.199 
  • Space Group: P 61
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 104.218α = 90
b = 104.218β = 90
c = 144.166γ = 120
Software Package:
Software NamePurpose
SERGUIdata collection
PHASERphasing
REFMACrefinement
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

View Full Validation Report



Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2009-09-22
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2023-09-06
    Changes: Data collection, Database references, Derived calculations, Refinement description