Homologous Cysteine-Containing Sequences in Tryptophanyl-tRNA Synthetases from <i>Escherichia coli</i> and Human Placentas

Abstract

The sequence Leu-Ala-Cys-Gly-Ile-Asx-Glx in a nonapeptide isolated from the tryptophanyl-tRNA synthetase of Escherichia coli B is homologous to the sequence Ile-Ala-Cys-Gly-Phe-Asx-Asx in a decapeptide isolated from the tryptophanyl-tRNA synthetase of human placenta. So far no homologies have been found between cysteine-containing peptides of aminoacyl-tRNA synthetases with different amino acid specificities.