Cysteinyl-tRNA synthetase (CARS)

Cysteinyl-tRNA synthetase (CARS) is a Class I aminoacyl-tRNA synthetase responsible for the essential step of protein synthesis: the attachment of L-cysteine to its cognate tRNA [UniProt: P49589]. This enzyme catalyzes a two-step reaction involving the formation of a cysteinyl-adenylate intermediate followed by the transfer of the cysteinyl group to the 3'-end of tRNA(Cys) [PubMed: 10591495]. Beyond its primary role in translation, CARS has been implicated in non-canonical functions such as cellular signaling and the stress response [PubMed: 25533954]. In medicine, CARS is a significant target for the development of antimicrobial and antiparasitic agents, as selective inhibition of the pathogen's version of the enzyme can halt its protein production [PubMed: 28846304]. Mutations in the human CARS1 and CARS2 genes are linked to various genetic disorders, including microcephaly and neurodevelopmental conditions, highlighting its critical role in human physiology [OMIM: 603128].

Other names

Cysteine--tRNA ligaseCARS1CYSRSCysteinyl-tRNA ligaseCARS

The primary mechanism of action involves the competitive inhibition of the enzyme's active site, preventing the binding of ATP or L-cysteine, which blocks the formation of the cysteinyl-adenylate intermediate and subsequent aminoacylation of tRNA [PubMed: 10591495].