Structural and functional relationships between aminoacyl-tRNA synthetases

Aminoacyl-tRNA synthetases can be divided in two groups of equal size on the basis of differences in the structure of their active sites, based on structural data (amino acid sequences and tertiary structures), which can be rationalized in functional terms.

Abstract

Aminoacyl-tRNA synthetases can be divided in two groups of equal size on the basis of differences in the structure of their active sites. The core of class I synthetases is the classical nucleotide-binding domain with its characteristic Rossmann fold. In contrast, the active site of class II synthetases is built around an antiparallel beta-sheet, to which the substrates bind. This classification, which is based on structural data (amino acid sequences and tertiary structures), can be rationalized in functional terms.