Open AccessBiochemistry of coenzyme B 12 ‐dependent glycerol and diol dehydratases and organization of the encoding genes
Author(s) -
Daniel Rolf,
Bobik Thomas A,
Gottschalk Gerhard
Publication year - 1998
Publication title -
fems microbiology reviews
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.91
H-Index - 212
eISSN - 1574-6976
pISSN - 0168-6445
DOI - 10.1111/j.1574-6976.1998.tb00387.x
Subject(s) - dehydratase , biochemistry , biology , gene , coenzyme a , stereochemistry , cofactor , glycerol , enzyme , chemistry , reductase
Glycerol and diol dehydratases exhibit a subunit composition of α 2 β 2 γ 2 and contain coenzyme B 12 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 B 12 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.