Tags: Protein.
The aminoacyl-tRNA synthetases (EC 6.1.1.) catalyse the attachment of an amino acid to its cognate transfer RNA molecule in a highly specific two-step reaction. These proteins differ widely in size and oligomeric state and have limited sequence homology. The 20 aminoacyl-tRNA synthetases are divided into two classes I and II. Class I aminoacyl-tRNA synthetases contain a characteristic Rossman fold catalytic domain and are mostly monomeric.