| abstract |
The method by which polypeptides having residues other than the 20 common amino acids are made is established. A leader peptide sequence, and its gene, are identified which induce or assist post-translational modifications of Cys, Thr and Ser in prokaryotes. The leader sequence may be used to induce the presence of covalent bonding sites in polypeptides and can be expressed by either naturally occurring or artificial means. |