Increased sequence conservation of domain repeats in prokaryotic proteins.

Protein domain repeats within a protein sequence have been observed throughout all domains of life. Our analysis shows a significantly higher degree of sequence identity between repeated domains in prokaryotes compared to eukaryotes. We discuss this difference in the light of aggregation prevention, contribution to functional divergence and binding-related functions. We then address the possible underlying features that create and conserve domain repeats. Our findings provide a starting point for the identification of the fundamental principles that underlie this basic difference between eukaryotic and prokaryotic protein evolution. Copyright 2010 Elsevier Ltd. All rights reserved.