Lipoate synthase

The current status of the overexpression and purification of lipoate synthase is summarized in the table. 

Enzymes in the radical SAM superfamily carry out a diverse set of reactions including sulfur insertion in biotin and lipoate synthases, DNA repair, tRNA modification, and are involved in the synthesis of molybdop-terin, heme, thiamine, and many natural products. Shepard and Broderick discuss the common themes in these reactions and differentiating details in the chapter. Despite the diversity of the reactions, they all begin with a... 

Sulfur Insertion Biotin Synthase and Lipoate Synthase 636... 

Biotin synthase (BioB) and lipoate synthase were two other enzymes that, prior to the identification of the superfamily, were shown to contain iron-sulfur clusters and to utilize SAM for catalyzing the radical-mediated insertion of sulfur into unactivated C-H bonds."" ... 

BioB and lipoate synthase represent a group of radical SAM enzymes that catalyze sulfur insertion reactions (Figure 4) and were among the group of enzymes identified early on to utilize iron-sulfur clusters and SAM in... 

The biotin and lipoate synthases catalyze similar reactions, the insertion of sulfur into unactivated C—bonds to generate essential cofactors (Figures 8C and 8D). The substrate in the case of biotin synthase is dethiobiotin, with a single sulfur inserted into two C— FI bonds to generate the tetrahydrothiophene ring of biotin. In the case of lipoate synthase, two atoms of sulfur are inserted, one each into the C—bonds at positions 6 and 8 of octanoic acid to produce dihydrolipoate, which is typically isolated in the oxidized form shown in Figure 8D. (The actual... 

The other members of the radical-SAM family have shown some, but not all, of the cluster properties observed for PFL-AE. For example, evidence for both [2Fe-2S] and [4Fe-4S] clusters have been reported for both biotin synthase and lipoate synthase. In fact, the [2Fe-2S] cluster in biotin synthase is quite stable, and thus biotin synthase can be purified aerobically with the [2Fe-2S] cluster intact, and then reconstituted anaerobically to generate the... 

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