Disease relevance of Coronamic acid

• Coronatine (COR) is a phytotoxin produced by several pathovars of Pseudomonas syringae and consists of coronafacic acid (CFA), an analog of methyl jasmonic acid (MeJA), and coronamic acid (CMA), which resembles 1-aminocyclopropane-1-carboxylic acid (ACC), a precursor to ethylene [1].
• Four adjacent open reading frames, cytC1-C4, were cloned from a cytotrienin-producing strain of a Streptomyces sp. by using primers derived from the conserved region of a gene encoding a nonheme iron halogenase, CmaB, in coronamic acid biosynthesis [2].

High impact information on Coronamic acid

• The enzyme expressed in the oocytes under the direction of plant RNA is indistinguishable from genuine plant EFE with regard to its saturation kinetics, its iron dependency and its stereospecificity to the diastereomeric ethyl derivatives of ACC, allocoronamic acid and coronamic acid [3].
• SyrC joins a growing family of such aminoacyl-shuttling enzymes that also use covalent catalysis to move aminoacyl groups from carrier proteins during coumermycin and coronamic acid biosynthesis [4].
• To assess the relative contributions of CFA, CMA, and COR in virulence, we constructed and characterized cfa6 cmaA double mutant strains [5].
• The region of the COR biosynthetic gene cluster proposed to be responsible for CMA biosynthesis was resequenced, and errors in previously deposited cmaA sequences were corrected [6].
• It is postulated that the L-allo-isoleucine covalently tethered to CmaA serves as the substrate for additional enzymes in the CMA biosynthetic pathway that catalyze cyclopropane ring formation, which is followed by thiolester hydrolysis, yielding free CMA [6].

Chemical compound and disease context of Coronamic acid

• Pseudomonas syringae pv. glycinea PG4180 produces the chlorosis-inducing phytotoxin coronatine (COR), which consists of a polyketide component, coronafacic acid (CFA), ligated by an amide bond to coronamic acid (CMA), an ethylcyclopropyl amino-acid derived from isoleucine [7].
• Pseudomonas syringae pv. glycinea PG4180 produces coronatine (COR), a chlorosis-inducing phytotoxin that consists of the polyketide coronafacic acid (CFA) coupled via an amide bond to the ethylcyclopropyl amino acid coronamic acid (CMA) [8].

Biological context of Coronamic acid

• The biosynthetic gene cluster for coronamic acid, an ethylcyclopropyl amino acid, contains genes homologous to amino acid-activating enzymes and thioesterases [9].
• This area was also conserved in the promoter region for cmaA, which encodes a transcript containing genes for coronamic acid synthesis, another intermediate in the COR biosynthetic pathway [10].
• We report the nucleotide sequence of a 2.37-kb region containing the coronafacate ligase-encoding gene (cfl) which is required for the amide linkage of CFA and CMA [7].
• Thermoregulation of the cfl/CFA operon and the coronamic acid biosynthetic gene cluster via the modified two-component regulatory system is discussed [11].

References