Glutathione S-transferase C-terminal-like, alpha helical domain of the Aminoacyl tRNA synthetase cofactor 1 and similar proteins
Glutathione S-transferase (GST) C-terminal domain family, Aminoacyl tRNA synthetase cofactor 1 (Arc1p)-like subfamily; Arc1p, also called GU4 nucleic binding protein 1 (G4p1) or p42, is a tRNA-aminoacylation and nuclear-export cofactor. It contains a domain in the N-terminal region with similarity to the C-terminal alpha helical domain of GSTs. This domain mediates the association of the aminoacyl tRNA synthetases (aaRSs), MetRS and GluRS, in yeast to form a stable stoichiometric ternany complex. The GST_C-like domain of Arc1p is a protein-protein interaction domain containing two binding sites which enable it to bind the two aaRSs simultaneously and independently. The MetRS-Arc1p-GluRS complex selectively recruits and aminoacylates its cognate tRNAs without additional cofactors. Arc1p also plays a role in the transport of tRNA from the nucleus to the cytoplasm. It may also control the subcellular distribution of GluRS in the cytoplasm, nucleoplasm, and the mitochondrial matrix.