Ribosomal Elongation of Aminobenzoic Acid Derivatives

2-Aminobenzoic acid
and heterocyclic amino acids are aromatic homologues
of β-amino acids, but their chemical properties are quite distinct.
Because of the poor nucleophilicity of the amino group conjugated
with the aromatic ring, no literature reports of their successful
ribosomal elongation in nascent peptide chains have appeared to date.
Here we report for the first time their incorporation in nascent peptide
chains by means of a reconstituted translation system in which a designer
tRNAPro1E2 capable of recruiting the elongation factors
EF-Tu and EF-P was charged with their derivatives and the corresponding
peptides were successfully expressed. We also demonstrate the expression
of macrocyclic peptides containing exotic amino acids, including aminobenzoic
acid derivatives.