Dihydrolipoamide dehydrogenase from the halophilic archaeon Haloferax volcanii: homologous overexpression of the cloned gene.

The gene encoding dihydrolipoamide dehydrogenase from the halophilic archaeon, Haloferax volcanii, has been subcloned and overexpressed in the parent organism by using the halophilic archaeal rRNA promoter. The recombinant protein has been purified to homogeneity and characterized with respect to its kinetic, molecular, and salt-dependent properties. A dihydrolipoamide dehydrogenase-minus mutant of H. volcanii has been created by homologous recombination with the subcloned gene after insertion of the mevinolin resistance determinant into the protein-coding region. To explore the physiological function of the dihydrolipoamide dehydrogenase, the growth properties of the mutant halophile have been examined.