Bacilysin is a non-ribosomally synthesized dipeptide antibiotic consisting of l-alanine residue at the N terminus and non-proteinogenic amino acid, l-anticapsin, at the C terminus linked by a peptide bond. It is known to be active against a wide range of bacteria and fungi and is synthesized by proteins in the bac operon of the gene cluster of the bacterial species Bacillus subtilis. This pathway shows the synthesis of bacilysin by B.subtilis and starts with the compound prephenate - the anionic form of prephenic acid and is an intermediate in the metabolism of many secondary metabolites. Its decarboxylation leads to the formation of the intermediates that lead up to the synthesis of the L-anticapsin intermediate that is produced by some Bacillus species and functions as a Trojan Horse antibiotic. Once inside the victim's cell, L-anticapsin is liberated by the action of peptidases and attacks the host so in order to protect the producers against inactivation of their own glucosamine synthase, L-alanine is ligated to the amino group of L-anticapsin, producing the benign dipeptide bacilysin. Bacilysin is excreted out of the cell and imported by the dipeptide permeases of susceptible bacterial or fungal cells. Bacilysin is then transported out of the B. subtilis cell via the transporter putative bacilysin exporter BacE.

Bacilysin Biosynthesis References