Seryl-tRNA synthetase， cytoplasmic（SARS) is a member of the class-II aminoacyl-tRNA synthetase family. Aminoacyl-tRNA synthetases’ role is to catalyze the aminoacylation of tRNAs by their corresponding amino acids， as a result linking amino acids with tRNA-contained nucleotide triplets. The SARS enzyme catalyzes the attachment of serine to tRNA（Ser). SARS enzyme is probably able to aminoacylate tRNA（Sec) with serine， to form the misacylated tRNA L-seryl-tRNA（Sec)， which will be then converted into selenocysteinyl-tRNA（Sec).
