Does a bacterial elongation factor share a common evolutionary ancestor with actin?

Abstract

Protein synthesis elongation factor Tu from E. coli shares several physical, chemical, and functional properties with actin-like proteins. Limited tryptic degradation indicartes that the two polypeptides have a similar molecular architecture. These observations suggest that they could have evolved from a common ancestor, although more information will be necessary to prove or disprove this hypothesis. A partial sequence, comprising 22 aminoacid residues from the aminoterminal end of the large tryptic fragment of elongation factor Tu is presented.