Glutamate synthase: a complex iron-sulfur flavoprotein

Cell Mol Life Sci. 1999 Apr;55(4):617-38. doi: 10.1007/s000180050319.


Glutamate synthase is a complex iron-sulfur flavoprotein that forms L-glutamate from L-glutamine and 2-oxoglutarate. It participates with glutamine synthetase in ammonia assimilation processes. The known structural and biochemical properties of glutamate synthase from Azospirillum brasilense, a nitrogen-fixing bacterium, will be discussed in comparison to those of the ferredoxin-dependent enzyme from photosynthetic tissues and of the eukaryotic reduced pyridine nucleotide-dependent form of glutamate synthase in order to gain insight into the mechanism of the glutamate synthase reaction. Sequence analyses also revealed that the small subunit of bacterial glutamate synthase may be the prototype of a novel class of flavin adenine dinucleotide- and iron-sulfur-containing oxidoreductase widely used as an enzyme subunit or domain to transfer reducing equivalents from NAD(P)H to an acceptor protein or protein domain.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Catalysis
  • Flavin-Adenine Dinucleotide / chemistry
  • Glutamate Synthase / physiology*
  • Iron-Sulfur Proteins / physiology*
  • Molecular Sequence Data
  • NADH, NADPH Oxidoreductases / chemistry
  • NADP / chemistry
  • Sequence Analysis


  • Iron-Sulfur Proteins
  • Flavin-Adenine Dinucleotide
  • NADP
  • Glutamate Synthase
  • NADH, NADPH Oxidoreductases