Valyl tRNA Synthetase 2, Mitochondrial (VARS2)

By sequencing clones obtained from a size-fractionated fetal brain cDNA library, Nagase et al. (2001) cloned VARS2, which they designated KIAA1885. The deduced 1,098-amino acid protein shares a high degree of similarity with human valyl-tRNA synthetase (VARS). RT-PCR ELISA detected nearly uniform VARS2 expression in all adult and fetal tissues and specific adult brain regions examined. By searching databases for aminoacyl-tRNA synthetases containing a mitochondrial targeting sequence, Bonnefond et al. (2005) identified VARS2, which the called mitochondrial VALRS. The deduced 993-amino acid protein has an N-terminal mitochondrial targeting signal with a predicted cleavage site after residue 29. VARS2 has characteristics of a class I mitochondrial aminoacyl-tRNA synthetase, including a classical Rossmann fold.