We have sequenced and expressed in Escherichia coli the gene encoding the seryl-tRNA synthetase from the pathogenic bacterium Staphylococcus aureus. The overexpressed and purified recombinant enzyme was able to aminoacylate unfractionated tRNA from E. coli. Its activity was not affected by antibodies raised against and inhibiting the E. coli seryl-tRNA synthetase. (C) 1998 Elsevier Science B.V.