2Institute of Protein Research, 142290 Pushchino, Moscow Region, Russia
* To whom correspondence should be addressed.
Received January 14, 2012; Revision received May 23, 2012
This review is devoted to substantiation of new characteristics for classification of living organisms. The novel view of a role of flexible regions in protein functioning and evolution is suggested. It is based on the newly revealed correlation between the number of loops in elongation factors and the complexity of organisms. This correlation allowed us to formulate a hypothesis of evolution of this protein family. In addition, the study of the ribosomal protein S1 family made it possible to consider the number of structural domains as a reliable indicator of a microorganism’s affiliation with a particular division and to judge about “direction” of their evolution. The findings allow us to consider the loops and repeats in these proteins as unique imprints of molecular evolution.
KEY WORDS: predicted loops, complexity of organisms, number of structural domains, reductive evolution