AdoCbl-dependent diol dehydratase (DD) (EC 4.2.1.28) is one of the enzymes that catalyzes the conversion of 1,2-propanediol, 1,2-ethanediol, and glycerol to the corresponding aldehydes. A DD-reactivating factor (DDR) is responsible for the rapid reactivation of the inactivated holoDD in the presence of AdoCbl, ATP, and Mg2+. DDR exists as a dimer of heterodimer (alpha-beta)2. The alpha subunit has four domains: ATPase domain, swiveling domain, linker domain, and insert domain. The beta subunit, composed of a single domain, has a similar fold to the beta subunit of diol dehydratase (DD). This entry describes the swiveling domain of DDR, which structurally connects the beta subunit and the ATPase domain of the other alpha subunit. Furthermore, the beta subunit moves with the swiveling domain while the linker domain acts as a flat spring or a hinge for the domain movement of the swiveling domain [1].

1: Release of a damaged cofactor from a coenzyme B12-dependent enzyme: X-ray structures of diol dehydratase-reactivating factor. Shibata N, Mori K, Hieda N, Higuchi Y, Yamanishi M, Toraya T; Structure. 2005;13:1745-1754. PMID:16338403