Glycerol dehydratase

In industrial processes, 1,3-propanediol is used for the production of polyester fibers, polyurethanes and cydic compounds [85]. 1,3-Propanediol can be produced from glucose with the limiting step catalyzed by glycerol dehydratase. A metagenomic survey for glycerol hydratases from the environment resulted in seven positive clones, one of which displayed a level of catalytic efficiency and stability making it ideal for application in the produdion of 1,3-propanediol from glucose. 

Glycerol dehydratase catalyzes the same type of reaction... 

The penultimate enzyme in the pathway, glycerol dehydratase (E. C. 4.2.1.30), catalyzing the dehydration of glycerol to 3-hydroxypropionaldehyde, is a vitamin B12-dependent, cyanocobalamin-containing enzyme, which employs a radical... 

H. Kajiura, K. Mori, T. Tobimatsu, and T. Toraya, Characterization and mechanism of action of a reactivating factor for adenosylcobalamin-dependent glycerol dehydratase, J. Biol. Chem. 2001, 276, 36514-36519. 

About 10 coenzyme B -dependent enzymes are now known (reviewed in References 13,14, and 76 see Table 1) four carbon skeleton mutases (methylmalonyl-CoA mutase (MMCM), glutamate mutase (GM), methylene glu-tarate mutase (MGM), isobutyryl-CoA mutase (ICM) ), diol dehydratase (DD), glycerol dehydratase, ethanol-amine anunonia lyase (EAL), two amino mutases, and Bi2-dependent ribonucleotide reductase. The coenzyme Bi2-dependent enzymes are unevenly distributed in the living world, and MMCM is the only enzyme that is also indispensable in human metabolism. ... 

Dial Dehydratases, Glycerol Dehydratase, and Ethanolamine Ammonia Lyase... 

Recently, a glycerol dehydratase was discovered in the anaerobic bacterium Clostridium butyricum, whose active site contains a glycyl radical formed by the action of the 5 -deoxyadenosyl radical on a specific glycine residue of the protein (20). The 5 -deoxyadenosyl radical is generated not from coenzyme Bi2, but by one-electron reduction of the stmcturally much simpler molecule 5-adenosylmethionine (SAM), named poor man s B12 by Barker. Hence, this glycerol dehydratase performs the same reaction, probably with a similar pathway, to the coenzyme B 12-dependent glycerol dehydratase. 

O Brien JR, Raynaud C, Croux C, Girbal L, Soucaille P, Lanzilotta WN. Insight into the mechanism of the B12-indepen-dent glycerol dehydratase from C. butyricum preliminary and structural characterization. Biochemistry 2004 43 4635-4645. 

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