Two reactions are simultaneously catalyzed by a single enzyme: the arginine-dependent simultaneous formation of two products, ethylene and succinate, from 2-oxoglutarate by an enzyme from Pseudomonas syringae

Biochem Biophys Res Commun. 1992 Oct 30;188(2):483-9. doi: 10.1016/0006-291x(92)91081-z.

Abstract

A single enzyme isolated from Pseudomonas syringae pv. phaseolicola PK2 simultaneously catalyzed two reactions, namely, the formation of ethylene and succinate from 2-oxoglutarate, at a molar ratio of 2:1. In the main reaction, 2-oxoglutarate was dioxygenated to produce one molecule of ethylene and three molecules of carbon dioxide. In the sub-reaction, both 2-oxoglutarate and L-arginine were mono-oxygenated to yield succinate plus carbon dioxide and L-hydroxyarginine, respectively, the latter being further transformed to guanidine and L-delta 1-pyrroline-5-carboxylate. We propose a dual-circuit mechanism for the entire reaction, in which the binding of L-arginine and 2-oxoglutarate in a Schiff-base structure generates a common intermediate for two reactions.

MeSH terms

  • Arginine / metabolism*
  • Ethylenes / metabolism*
  • Ketoglutaric Acids / metabolism*
  • Kinetics
  • Lyases / isolation & purification
  • Lyases / metabolism*
  • Pseudomonas / enzymology*
  • Succinates / metabolism*
  • Succinic Acid

Substances

  • Ethylenes
  • Ketoglutaric Acids
  • Succinates
  • ethylene
  • Arginine
  • Succinic Acid
  • Lyases
  • ethylene forming enzyme