Histidyl tRNA Synthetase 2, Mitochondrial (HARS2)

HARS2 is an enzyme belonging to the class II family of aminoacyl-tRNA synthetases. Functioning in the synthesis of histidyl-transfer RNA, the enzyme plays an accessory role in the regulation of protein biosynthesis. The gene is located in a head-to-head orientation with HARS on chromosome five, where the homologous genes share a bidirectional promoter.

The deduced 506-amino acid HO3 protein has a calculated molecular mass of 56.9 kD. HO3 shares 72% amino acid identity with HARS. Both proteins contain 3 motifs conserved among class II aminoacyl-tRNA synthetases and 2 signature regions of histidyl-tRNA synthetases. However, HARS and HARS2 have divergent N-terminal domains that are encoded by the first 2 exons of each gene.