The enzyme propanediol dehydratase () catalyzes the chemical reaction
This enzyme belongs to the family of lyases, specifically the hydro-lyases, which cleave carbon-oxygen bonds. The systematic name of this enzyme class is propane-1,2-diol hydro-lyase (propanal-forming). Other names in common use include meso-2,3-butanediol dehydrase, diol dehydratase, <small>DL</small>-1,2-propanediol hydro-lyase, diol dehydrase, adenosylcobalamin-dependent diol dehydratase, propanediol dehydrase, coenzyme B<sub>12</sub>-dependent diol dehydrase, 1,2-propanediol dehydratase, dioldehydratase, and propane-1,2-diol hydro-lyase. This enzyme participates in glycerolipid metabolism. It employs one cofactor, cobamide.
As of late 2007, 7 structures have been solved for this class of enzymes, with PDB accession codes , , , , , , and .