5lun

Publication Abstract from PubMed

Ethylene is important in industry and biological signaling. In plants, ethylene is produced by oxidation of 1-aminocyclopropane-1-carboxylic acid, as catalyzed by 1-aminocyclopropane-1-carboxylic acid oxidase. Bacteria catalyze ethylene production, but via the four-electron oxidation of 2-oxoglutarate to give ethylene in an arginine-dependent reaction. Crystallographic and biochemical studies on the Pseudomonas syringae ethylene-forming enzyme reveal a branched mechanism. In one branch, an apparently typical 2-oxoglutarate oxygenase reaction to give succinate, carbon dioxide, and sometimes pyrroline-5-carboxylate occurs. Alternatively, Grob-type oxidative fragmentation of a 2-oxoglutarate-derived intermediate occurs to give ethylene and carbon dioxide. Crystallographic and quantum chemical studies reveal that fragmentation to give ethylene is promoted by binding of l-arginine in a nonoxidized conformation and of 2-oxoglutarate in an unprecedented high-energy conformation that favors ethylene, relative to succinate formation.

Structural and stereoelectronic insights into oxygenase-catalyzed formation of ethylene from 2-oxoglutarate.,Zhang Z, Smart TJ, Choi H, Hardy F, Lohans CT, Abboud MI, Richardson MSW, Paton RS, McDonough MA, Schofield CJ Proc Natl Acad Sci U S A. 2017 May 2;114(18):4667-4672. doi:, 10.1073/pnas.1617760114. Epub 2017 Apr 18. PMID:28420789^[2]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.