A characteristic difference among GroEL homologs from intracellular symbionts of closely-interrelated species of aphid

Abstract

Nucleotide sequences encoding GroEL homologs of intracellular symbionts in three closely interrelated aphids were compared with one another and that for GroEL. It was suggested that in these proteins a particular position is highly susceptible to amino acid substitution, through which the GroEL homologs of symbionts seemed to have acquired a unique function on top of the activity as molecular chaperone. This may represent a rare example of non-neutral evolution of molecule under the positive selection pressure.