Catalyzes the ATP-dependent ligation of cysteine to tRNA(Cys). ATP + L-cysteine + tRNA(Cys) = AMP + diphosphate + L-cysteinyl-tRNA(Cys) Binds 1 zinc ion per subunit. Homodimer. The disease is caused by variants affecting the gene represented in this entry. A chromosomal aberration involving CARS is associated with inflammatory myofibroblastic tumors (IMTs). Translocation t(2;11)(p23;p15) with ALK. Found in 20% of the mRNAs. Belongs to the class-I aminoacyl-tRNA synthetase family.