Lasso PeptidesLasso peptides form a growing family of fascinating ribosomally synthesized and post translationally modified peptides produced by bacteria. They contain 15 to 24 residues and share a unique interlocked topology that involves an N terminal 7 to 9 residue macrolactam ring where the C terminal tail is threaded and irreversibly trapped. The ring results from the condensation of the N terminal amino group with a side chain carboxylate of a glutamate at