Characterization of a Mycoplasma hominis gene encoding lysyl-tRNA synthetase (LysRS)

The gene encoding lysyl-tRNA synthetase (lysS) in Mycoplasma hominis was cloned and sequenced. The gene was found to have an open reading frame of 1466 bp encoding a polypeptide with a predicted molecular mass of 57 kDa. The amino acid sequence showed 44.3% and 43.7% identity to the Escherichia coli lysyl-tRNA synthetases, encoded by lysS and lysU. Only one lysyl-tRNA synthetase encoding gene was found in M. hominis. The G + C content of the gene was found to be 28.6%, which is significantly lower than in other prokaryotes. The gene was located 4 kb upstream of the M. hominis PG21 rRNA B operon.