1S4Y

Crystal structure of the activin/actrIIb extracellular domain


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.286 
  • R-Value Work: 0.206 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

A Flexible Activin Explains the Membrane-Dependent Cooperative Assembly of TGF-beta Family Receptors.

Greenwald, J.Vega, M.E.Allendorph, G.P.Fischer, W.H.Vale, W.Choe, S.

(2004) Mol.Cell 15: 485-489

  • DOI: 10.1016/j.molcel.2004.07.011

  • PubMed Abstract: 
  • A new crystal structure of activin in complex with the extracellular domain of its type II receptor (ActRIIb-ECD) shows that the ligand exhibits an unexpected flexibility. The motion in the activin dimer disrupts its type I receptor interface, which ...

    A new crystal structure of activin in complex with the extracellular domain of its type II receptor (ActRIIb-ECD) shows that the ligand exhibits an unexpected flexibility. The motion in the activin dimer disrupts its type I receptor interface, which may account for the disparity in its affinity for type I versus type II receptors. We have measured the affinities of activin and its antagonist inhibin for ActRIIb-ECD and found that the affinity of the 2-fold symmetric homodimer activin for ActRIIb-ECD depends on the availability of two spatially coupled ActRIIb-ECD molecules, whereas the affinity of the heterodimer inhibin does not. Our results indicate that activin's affinity for its two receptor types is greatly influenced by their membrane-restricted setting. We propose that activin affinity is modulated by the ligand flexibility and that cooperativity is achieved by binding to two ActRII chains that immobilize activin in a type I binding-competent orientation.


    Organizational Affiliation

    Structural Biology Laboratory, The Salk Institute, La Jolla, CA 92037, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Activin receptor type IIB precursor
A, C
98Mus musculusMutation(s): 0 
Gene Names: Acvr2b
EC: 2.7.11.30
Find proteins for P27040 (Mus musculus)
Go to UniProtKB:  P27040
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Inhibin beta A chain
B, D
116Homo sapiensMutation(s): 0 
Gene Names: INHBA
Find proteins for P08476 (Homo sapiens)
Go to Gene View: INHBA
Go to UniProtKB:  P08476
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.286 
  • R-Value Work: 0.206 
  • Space Group: P 21 21 2
Unit Cell:
Length (Å)Angle (°)
a = 86.290α = 90.00
b = 120.627β = 90.00
c = 43.550γ = 90.00
Software Package:
Software NamePurpose
REFMACrefinement
HKL-2000data reduction
EPMRphasing
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2004-08-10
    Type: Initial release
  • Version 1.1: 2008-04-29
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Advisory, Version format compliance