Glutamate synthase: a fascinating pathway from L-glutamine to L-glutamate

Cell Mol Life Sci. 2004 Mar;61(6):669-81. doi: 10.1007/s00018-003-3316-0.

Abstract

Glutamate synthase is a multicomponent iron-sulfur flavoprotein belonging to the class of N-terminal nucleophile amidotransferases. It catalyzes the conversion of L-glutamine and 2-oxoglutarate into two molecules of L-glutamate. In recent years the X-ray structures of the ferredoxin-dependent glutamate synthase and of the a subunit of the NADPH-dependent glutamate synthase have become available. Thanks to X-ray crystallography, it is now known that the ammonia reaction intermediate is transferred via an intramolecular tunnel from the amidotransferase domain to the synthase domain over a distance of about 32A. Although ammonia channeling is a recurrent theme for N-terminal nucleophile and triad-type amidotransferases, the molecular mechanisms of ammonia transfer and its control are different for each known amidotransferase. This review focuses on the intriguing mechanism of action and self-regulation of glutamate synthase with a special focus on the structural data.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Catalytic Domain
  • Glutamate Synthase / chemistry
  • Glutamate Synthase / metabolism*
  • Glutamic Acid / metabolism*
  • Glutamine / metabolism*
  • Ligands
  • Models, Molecular
  • Oxidation-Reduction
  • Protein Conformation
  • Signal Transduction*

Substances

  • Ligands
  • Glutamine
  • Glutamic Acid
  • Glutamate Synthase