GARS is an（alpha)2 dimer which is a member of the class II family of tRNA synthetases. GARS is a glycyl-tRNA synthetase， one of the aminoacyl-tRNA synthetases which charge tRNAs with their cognate amino acids. GARS catalyzes the attachment of glycine to tRNA（Gly). In addition， GARS is able to produce diadenosine tetraphosphate（Ap4A)， which is a universal pleiotropic signaling molecule required for cell regulation pathways， by direct condensation of two ATPs. GARS has been demonstrated to be a target of autoantibodies in the human autoimmune diseases， polymyositis or dermatomyositis.
