The Evolution of Protein Structures

  1. C. Chothia*, and
  2. A.M. Lesk*,
  1. *MRC Laboratory of Molecular Biology, Cambridge CB2 2QH, England; Christopher Ingold Laboratory, University College London, London WC1H OAJ, England; Biocomputing Programme, European Molecular Biology Laboratory, Heidelberg, Federal Republic of Germany

This extract was created in the absence of an abstract.

Excerpt

As proteins evolve, their amino acid sequences change. These changes can be large—so large that members of the same protein family may have less than one-fifth of the residues at homologous sites are identical. In most instances, the large sequence changes result in no more than a modification of functional properties. How do very different sequences give proteins with similar structures and functions? To answer this question we analyzed in detail the atomic structure of homologous proteins. We determined the effects of the sequence differences on the structures of these proteins. The analyses showed that sequence changes are accommodated by changes in structure.

In this paper, we describe in outline the structural changes that occur during evolution and discuss how their nature and extent are determined by the intrinsic properties of proteins. We also show how, in distantly related proteins, where the structural differences are large, their basic functional properties...

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