Journal of Molecular Evolution

, Volume 40, Issue 3, pp 238–248

The expanding small heat-shock protein family, and structure predictions of the conserved “α-crystallin domain”

  • Gert-Jan Caspers
  • Jack A. M. Leunissen
  • Wilfried W. de Jong

DOI: 10.1007/BF00163229

Cite this article as:
Caspers, GJ., Leunissen, J.A.M. & de Jong, W.W. J Mol Evol (1995) 40: 238. doi:10.1007/BF00163229


The ever-increasing number of proteins identified as belonging to the family of small heat-shock proteins (shsps) and α-crystallins enables us to reassess the phylogeny of this ubiquitous protein family. While the prokaryotic and fungal representatives are not properly resolved, most of the plant and animal shsps and related proteins are clearly grouped in distinct clades, reflecting a history of repeated gene duplications. The members of the shsp family are characterized by the presence of a conserved homologous “α-crystallin domain,” which sometimes is present in duplicate. Predictions are made of secondary structure and solvent accessibility of this domain, which together with hydropathy profiles and intron positions support the presence of two similar hydrophobic β-sheet-rich motifs, connected by a hydrophilic α-helical region. Together with an overview of the newly characterized members of the shsp family, these data help to define this family as being involved as stable structural proteins and as molecular chaperones during normal development and induced under pathological and stressful conditions.

Key words

Molecular chaperones Molecular phylogeny Molecular evolution Structural domains Structure prediction 

Copyright information

© Springer-Verlag New York Inc. 1995

Authors and Affiliations

  • Gert-Jan Caspers
    • 1
  • Jack A. M. Leunissen
    • 2
  • Wilfried W. de Jong
    • 1
    • 3
  1. 1.Department of BiochemistryUniversity of NijmegenNijmegenThe Netherlands
  2. 2.CAOS/CAMM CenterUniversity of NijmegenNijmegenThe Netherlands
  3. 3.Institute of Taxonomic ZoologyUniversity of AmsterdamAmsterdamThe Netherlands

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