The succinate dehydrogenase complex, also known as Complex II, functions in both the citric acid cycle and the electron transport chain which couples to ATP synthesis in the oxidative phosphorylation pathway. Four subunits make up the complex: Sdha, Sdhb, Sdhc and Sdhd. The first contains a flavin adenine dinucleotide (FAD) cofactor and the succinate binding site, the second contains the iron-sulfur clusters, the third and fourth are integral membrane protein anchors. The four genes are listed with aliases in parentheses, full names and links to report pages:

Sdha (Sdhf, Sdh2) – succinate dehydrogenase complex flavoprotein subunit A
Sdhb (Sdh1, Sdhip, Pgl4) – succinate dehydrogenase complex iron sulfur subunit B
Sdhc (Pgl3, Sdh3) – succinate dehydrogenase complex subunit C
Sdhd (Pgl1, Sdh4) – succinate dehydrogenase complex subunit D