This all alpha helical domain is the anticodon binding domain in Arginyl and glycyl tRNA synthetase. This domain is known as the DALR domain after characteristic conserved amino acids [1].

1: Evolution of aminoacyl-tRNA synthetases--analysis of unique domain architectures and phylogenetic trees reveals a complex history of horizontal gene transfer events. Wolf YI, Aravind L, Grishin NV, Koonin EV; Genome Res 1999;9:689-710. PMID:10447505