1E7N

The N-terminal domain of beta-B2-crystallin resembles the putative ancestral homodimer


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.35 Å
  • R-Value Free: 0.246 
  • R-Value Work: 0.212 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

The N-Terminal Domain of Betab2-Crystallin Resembles the Putative Ancestral Homodimer.

Clout, N.J.Basak, A.Wieligmann, K.Bateman, O.A.Jaenicke, R.Slingsby, C.

(2000) J.Mol.Biol. 304: 253

  • DOI: 10.1006/jmbi.2000.4197

  • PubMed Abstract: 
  • betagamma-crystallins from the eye lens are proteins consisting of two similar domains joined by a short linker. All three-dimensional structures of native proteins solved so far reveal similar pseudo-2-fold pairing of the domains reflecting their pr ...

    betagamma-crystallins from the eye lens are proteins consisting of two similar domains joined by a short linker. All three-dimensional structures of native proteins solved so far reveal similar pseudo-2-fold pairing of the domains reflecting their presumed ancient origin from a single-domain homodimer. However, studies of engineered single domains of members of the betagamma-crystallin superfamily have not revealed a prototype ancestral solution homodimer. Here we report the 2.35 A X-ray structure of the homodimer of the N-terminal domain of rat betaB2-crystallin (betaB2-N). The two identical domains pair in a symmetrical manner very similar to that observed in native betagamma-crystallins, where N and C-terminal domains (which share approximately 35% sequence identity) are related by a pseudo-2-fold axis. betaB2-N thus resembles the ancestral prototype of the betagamma-crystallin superfamily as it self-associates in solution to form a dimer with an essentially identical domain interface as that between the N and C domains in betagamma-crystallins, but without the benefit of a covalent linker. The structure provides further evidence for the role of two-domain pairing in stabilising the protomer fold. These results support the view that the betagamma-crystallin superfamily has evolved by a series of gene duplication and fusion events from a single-domain ancestor capable of forming homodimers.


    Organizational Affiliation

    Department of Crystallography, Birkbeck College, Malet Street, London, WC1E 7HX, UK.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
BETA-CRYSTALLIN B2
A, B
106Mus musculusGene Names: Crybb2
Find proteins for P62696 (Mus musculus)
Go to UniProtKB:  P62696
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.35 Å
  • R-Value Free: 0.246 
  • R-Value Work: 0.212 
  • Space Group: P 65
Unit Cell:
Length (Å)Angle (°)
a = 110.960α = 90.00
b = 110.960β = 90.00
c = 29.880γ = 120.00
Software Package:
Software NamePurpose
CNSrefinement
CNSphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2000-10-05
    Type: Initial release
  • Version 1.1: 2011-07-07
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance