Swapping of three-dimensional domains as a molecular mechanism of dimerization of aminoacyl-tRNA synthetases

It has been shown recently that many proteins undergo oligomerization through exchange of structural elements. That process, termed a 3D domain swapping, is the replacement of a portion of the tertiary structure of a protein with an identical piece from a second polypeptide chain. When the exchange is reciprocated, domain-swapped dimers embrace with the exchange of elements of secondary structure or domains; however, if the exchange is not reciprocated but propagated along multiple polynucleotide chains, higher-order assemblies may form. In this paper we discuss swapping as a general mechanism of aminoacyl-tRNA synthetases dimerization, specifically plant methionyl-tRNA synthetase.