Coronatine (COR) is a novel phytotoxin produced by several pathovars (pvs.) of Pseudomonas syringae and is a pathogenicity or virulence factor in plant diseases caused by these organisms. The two major components of COR, coronafacic acid (CFA) and coronamic acid (CMA), have distinctly different biosynthetic origins. CFA has a bicyclic structure and is synthesized as a branched polyketide through an undetermined sequence of events. CMA, an ethylcyclopropyl amino acid, is derived from the isoleucine biosynthetic pathway and cyclized via an unknown mechanism. Both CFA and CMA function as defined intermediates in the COR pathway and can be used in substrate feeding studies to relieve the biosynthetic block in COR- mutants.
Liyanage et al., 1995