2V95

Structure of Corticosteroid-Binding Globulin in complex with Cortisol


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.93 Å
  • R-Value Free: 0.264 
  • R-Value Work: 0.210 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Corticosteroid-Binding Globulin: Structural Basis for Steroid Transport and Proteinase-Triggered Release

Klieber, M.A.Underhill, C.Hammond, G.L.Muller, Y.A.

(2007) J.Biol.Chem. 282: 29594

  • DOI: 10.1074/jbc.M705014200

  • PubMed Abstract: 
  • Corticosteroid-binding globulin (CBG) is a serine proteinase inhibitor (serpin) family member that transports glucocorticoids in blood and regulates their access to target cells. The 1.9A crystal structure of rat CBG shows that its steroid-binding si ...

    Corticosteroid-binding globulin (CBG) is a serine proteinase inhibitor (serpin) family member that transports glucocorticoids in blood and regulates their access to target cells. The 1.9A crystal structure of rat CBG shows that its steroid-binding site resembles the thyroxin-binding site in the related serpin, thyroxin-binding globulin, and mutagenesis studies have confirmed the contributions of key residues that constitute the steroid-binding pocket. Unlike thyroxin-bound thyroxin-binding globulin, the cortisol-bound CBG displays an "active" serpin conformation with the proteinase-sensitive, reactive center loop (RCL) fully expelled from the regulatory beta-sheet A. Moreover, the CBG structure allows us to predict that complete insertion of the proteolytically cleaved RCL into the serpin fold occurs in concert with a displacement and unwinding of helix D that would disrupt the steroid-binding site. This allosteric coupling between RCL positioning and occupancy of the CBG steroid-binding site, which resembles the ligand (glycosamino-glycan)-dependent activation of the thrombin inhibitory serpins heparin cofactor II and anti-thrombin RCLs, ensures both optimal recognition of CBG by target proteinases and efficient release of steroid to sites of action.


    Organizational Affiliation

    Lehrstuhl für Biotechnik, Department of Biology, Friedrich-Alexander-University Erlangen-Nuremberg, D-91052 Erlangen, Germany.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
CORTICOSTEROID-BINDING GLOBULIN
A
371Rattus norvegicusMutation(s): 2 
Gene Names: Serpina6 (Cbg)
Find proteins for P31211 (Rattus norvegicus)
Go to UniProtKB:  P31211
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
HCY
Query on HCY

Download SDF File 
Download CCD File 
A
(11alpha,14beta)-11,17,21-trihydroxypregn-4-ene-3,20-dione
CORTISOL
C21 H30 O5
JYGXADMDTFJGBT-VWUMJDOOSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
PDNKd: 5 nM PDBBIND
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.93 Å
  • R-Value Free: 0.264 
  • R-Value Work: 0.210 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 122.110α = 90.00
b = 54.250β = 97.16
c = 61.040γ = 90.00
Software Package:
Software NamePurpose
REFMACrefinement
AMoREphasing
XDSdata reduction
XSCALEdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2007-09-04
    Type: Initial release
  • Version 1.1: 2015-12-02
    Type: Derived calculations, Other, Refinement description, Structure summary, Version format compliance