At least 6 amino acid operons are known to be regulated by attenuation.

[1] In each a leader sequence of 150–200 bp is found upstream of the first gene in the operon.

In each case the leader also codes for very short peptide sequence that is rich in the end product amino acid of the operon.

This structure forms when the cell has an excess of the regulatory amino acid and ribosome movement over the leader transcript is not impeded.

[1] When there is a deficiency of the charged tRNA of the regulatory amino acid the ribosome translating the leader peptide stalls and the antiterminator structure can form.