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 
  • R-Value Observed: 0.212 

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This is version 1.3 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
  • Primary Citation of Related Structures:  
    1E7N

  • 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 presumed ancient origin from a single-domain homodimer ...

    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
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Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
BETA-CRYSTALLIN B2A, B106Mus musculusMutation(s): 0 
Gene Names: Crybb2
UniProt
Find proteins for P62696 (Mus musculus)
Explore P62696 
Go to UniProtKB:  P62696
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP62696
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.35 Å
  • R-Value Free: 0.246 
  • R-Value Work: 0.212 
  • R-Value Observed: 0.212 
  • Space Group: P 65
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 110.96α = 90
b = 110.96β = 90
c = 29.88γ = 120
Software Package:
Software NamePurpose
CNSrefinement
CNSphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2000-10-05
    Type: Initial release
  • Version 1.1: 2011-07-07
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2018-05-30
    Changes: Data collection