Histidine–tRNA ligase, cytoplasmic, also called histidyl-tRNA synthetase 1, is an enzyme which in humans is encoded by the HARS1 gene (previously HARS). As a histidine–tRNA ligase, this enzyme functions to attach the amino acid histidine to its corresponding (cognate) transfer RNA (tRNAHis), which is required for RNA-to-protein translation.
Function
Aminoacyl-tRNA synthetases are a class of enzymes that charge tRNAs with their cognate amino acids. The protein encoded by this gene is a cytoplasmic enzyme which belongs to the class II family of aminoacyl tRNA synthetases. The enzyme is responsible for the synthesis of histidyl-transfer RNA, which is essential for the incorporation of histidine into proteins. The gene is located in a head-to-head orientation with HARS2 on chromosome five, where the homologous genes share a bidirectional promoter.
Clinical significance
The gene product is a frequent target of autoantibodies in the human autoimmune disease polymyositis/dermatomyositis. Pathogenic mutations in HARS1 are the cause of Type IIIB usher syndrome (USH3B), which is associated with progressive hearing and vision loss.
Interactions
HARS has been shown to interact with EEF1B2 and EEF1G.
See also Histidine–tRNA ligase, mitochondrial
References
Further reading