Multiple forms of lysyl-tRNA synthetase from Escherichia coli

Lysyl-tRNA synthetase has been isolated from E. coli. The enzymatic activity elutes as three or four bands from a hydroxyl-apatite column. Polyacrylamide gel analysis shows that each of these bands contain more than one enzymatically active protein species. The molecular weights of the subunits of these species provides an explanation for the variation in the molecular weights previously reported for this enzyme.