This family of archaeal proteins resembles known phenylalanyl-tRNA synthetase alpha chains. Recently, it was shown to act in a proposed pathway of tRNA(Cys) indirect aminoacylation, resulting in Cys biosynthesis from O-phosphoserine, in certain archaea. It charges tRNA(Cys) with O-phosphoserine. The pscS gene product converts the phosphoserine to Cys. [Amino acid biosynthesis, Serine family, Protein synthesis, tRNA aminoacylation]
Lu S et al.(2020). "CDD/SPARCLE: the conserved domain database in 2020.",