Succinate dehydrogenase/fumarate reductase, alpha/adenylylsulphate reductase subunit (IPR030664)

Short name: SdhA/FrdA/AprA

Family relationships


Two distinct, membrane-bound, FAD-containing enzymes are responsible for the catalysis of fumarate and succinate interconversion; the fumarate reductase is used in anaerobic growth, and the succinate dehydrogenase is used in aerobic growth [PMID: 9811659]. Succinate dehydrogenase (Sdh), a primary respiratory dehydrogenase, catalyses electron transfer from succinate to membrane-bound quinone. Fumarate reductase (Frd) catalyses the opposite reaction.

The enzyme complex consists at least of four subunits. The hydrophilic catalytic domain consists of a flavoprotein that contains covalently bound FAD and an active site of the enzyme [PMID: 5533923, PMID: 1375942].

Adenylylsulphate (APS) reductase catalyses reversibly the two-electron reduction of APS to sulphite and AMP during dissimilatory sulphate reduction or sulphur oxidation. Found in several bacterial lineages and in Archaeoglobales, APS reductase is a heterodimer composed of an alpha subunit containing a noncovalently bound FAD, and a beta subunit containing two [4Fe-4S] clusters. The alpha subunit of APS reductase shares a common evolutionary origin with fumarate reductase/succinate dehydrogenase flavoproteins [PMID: 10802060].

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.