The lipoamide arm in the glycine decarboxylase complex is not freely swinging

Nat Struct Biol. 1995 Jan;2(1):63-8. doi: 10.1038/nsb0195-63.


Glycine decarboxylase consists of four protein components. Its structural and mechanistic heart is provided by the lipoic acid-containing H-protein which undergoes a cycle of reductive methylamination, methylamine transfer and electron transfer. Lipoic acid attached to a specific lysine side chain is assumed to act as a 'swinging arm' conveying the reactive dithiolane ring from one catalytic centre to another. The X-ray crystal structures of two forms of the H-protein have been determined. The lipoate cofactor is located in the loop of a hairpin configuration but following methylamine transfer it is pivoted to bind into a cleft at the surface of the H-protein. The lipoamide-methylamine arm is, therefore, not free to move in aqueous solvent.

Publication types

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

MeSH terms

  • Amino Acid Oxidoreductases / chemistry*
  • Amino Acid Sequence
  • Animals
  • Bacterial Proteins / chemistry
  • Carrier Proteins / chemistry*
  • Cattle
  • Chickens
  • Computer Simulation
  • Crystallization
  • Crystallography, X-Ray
  • Flavin-Adenine Dinucleotide / metabolism
  • Glycine Decarboxylase Complex
  • Glycine Decarboxylase Complex H-Protein
  • Glycine Dehydrogenase (Decarboxylating)
  • Humans
  • Methylamines / chemistry
  • Models, Molecular
  • Molecular Sequence Data
  • Motion
  • Mutagenesis, Site-Directed
  • Plant Proteins / chemistry*
  • Protein Conformation*
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Solvents
  • Thioctic Acid / chemistry*


  • Bacterial Proteins
  • Carrier Proteins
  • Glycine Decarboxylase Complex H-Protein
  • Methylamines
  • Plant Proteins
  • Solvents
  • Flavin-Adenine Dinucleotide
  • Thioctic Acid
  • methylamine
  • Amino Acid Oxidoreductases
  • Glycine Decarboxylase Complex
  • Glycine Dehydrogenase (Decarboxylating)