S15/NS1/EPRS_RNA-binding domain. This short domain consists of a helix-turn-helix structure, which can bind to several types of RNA. It is found in the ribosomal protein S15, the influenza A viral nonstructural protein (NSA) and in several eukaryotic aminoacyl tRNA synthetases (aaRSs), where it occurs as a single or a repeated unit. It is involved in both protein-RNA interactions by binding tRNA and protein-protein interactions in the formation of tRNA-synthetases into multienzyme complexes. While this domain lacks significant sequence similarity between the subgroups in which it is found, they share similar electrostatic surface potentials and thus are likely to bind to RNA via the same mechanism.
Jiyao W et al.(2023). "The conserved domain database in 2023.",