Chemotactic response of Escherichia coli to chemically synthesized amino acids

In Escherichia coli, seven of the commonly occurring amino acids are strong attractants: L-aspartate, L-serine, L-glutamate, L-alanine, L-asparagine, glycine, and L-cysteine, in order of decreasing effectiveness. The chemotactic response to each amino acid attractant is mediated by either methyl-accepting chemotaxis protein I or II, but not by both. Seven of the commonly occurring amino acids are repellents. This work was carried out with chemically synthesized amino acids.