This is a region found N terminal to the catalytic domain of glutaminyl-tRNA synthetase (EC 6.1.1.18) in eukaryotes but not in Escherichia coli. This region is thought to bind RNA in a non-specific manner, enhancing interactions between the tRNA and enzyme, but is not essential for enzyme function [1].

1: Species barrier to RNA recognition overcome with nonspecific RNA binding domains. Wang CC, Schimmel P; J Biol Chem 1999;274:16508-16512. PMID:10347214