This two-domain protein from the bacterium?Pseudomonas syringae?contains an adenylation domain (A domain) and a thiolation domain (T domain). It catalyses the adenylation of?L-allo-isoleucine and its attachment to the T domain. The enzyme is involved in the biosynthesis of the toxin coronatine, which mimics the plant hormone jasmonic acid isoleucine. Coronatine promotes opening of the plant stomata allowing bacterial invasion, which is followed by bacterial growth in the apoplast, systemic susceptibility, and disease.
![Example Structure of L-allo-isoleucine-holo-[CmaA peptidyl-carrier protein] ligase EC#: 6.2.1.46](/wp-content/uploads/enzyme-structure/6.2.1.46.jpg)