InterPro domain: IPR033731

Glycyl-tRNA synthetase (GlyRS) functions as a homodimer in eukaryotes, archaea and some bacteria and as a heterotetramer in the remainder of prokaryotes. It is responsible for the attachment of glycine to the 3' OH group of ribose of the appropriate tRNA. The core catalytic domain is primarily responsible for ATP binding and hydrolysis. GlyRS has been assigned to class II aminoacyl-tRNA synthetases (aaRS) based upon its structure and the presence of three characteristic sequence motifs [ 1 , 2 , 3 ].

This glycyl-tRNA synthetase (GlyRS)-like domain includes the core catalytic domain of class II glycyl-tRNA synthetases (GlyRS) that form homodimers. The heterotetramer glyQ is in a different family of class II aaRS. This domain is also found at the N terminus of the accessory subunit of mitochondrial polymerase gamma (Pol gamma b). Pol gamma b stimulates processive DNA synthesis and is functional as a homodimer, which can associate with the catalytic subunit Pol gamma alpha to form a heterotrimer. Despite significant both structural and sequence similarity with GlyRS,Pol gamma b lacks conservation of several class II functional residues [ 4 ].

1. Eleven down and nine to go. Nat. Struct. Biol. 2, 824-31
2. Evolution of aminoacyl-tRNA synthetases--analysis of unique domain architectures and phylogenetic trees reveals a complex history of horizontal gene transfer events. Genome Res. 9, 689-710
3. Genomics and the evolution of aminoacyl-tRNA synthesis. Acta Biochim. Pol. 48, 313-21
4. DNA binding properties of human pol gammaB. J. Biol. Chem. 277, 50008-14