Biochemistry of coenzyme B12-dependent glycerol and diol dehydratases and organization of the encoding genes

FEMS Microbiol Rev. 1998 Dec;22(5):553-66. doi: 10.1111/j.1574-6976.1998.tb00387.x.


Glycerol and diol dehydratases exhibit a subunit composition of alpha 2 beta 2 gamma 2 and contain coenzyme B12 in the base-on form. The dehydratase reaction proceeds via a radical mechanism. The dehydratases are subject to reaction inactivation by the substrate glycerol which is caused by a cessation of the catalytic cycle because coenzyme B12 is not regenerated, instead 5'-deoxyadenosine and a catalytically inactive cobalamin are formed. The genetic organization of the dehydratase genes is quite similar in all organisms. Downstream of the dehydratase genes an open reading frame encoding a polypeptide of approximately 600 amino acids was identified which is apparently involved in the reactivation of suicide-inactivated enzyme.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Bacteria, Anaerobic / enzymology*
  • Bacteria, Anaerobic / genetics
  • Biodegradation, Environmental
  • Cobamides / metabolism
  • Glycerol / metabolism
  • Hydro-Lyases / chemistry
  • Hydro-Lyases / genetics*
  • Hydro-Lyases / metabolism*
  • Molecular Sequence Data
  • Propanediol Dehydratase / chemistry
  • Propanediol Dehydratase / genetics*
  • Propanediol Dehydratase / metabolism*
  • Propylene Glycol / metabolism


  • Cobamides
  • Propylene Glycol
  • Hydro-Lyases
  • Propanediol Dehydratase
  • glycerol dehydratase
  • cobamamide
  • Glycerol