Contributes to succinate dehydrogenase (quinone) activity. Involved in several processes, including defense response to other organism; determination of adult lifespan; and regulation of response to oxidative stress. Located in mitochondrion. Human ortholog(s) of this gene implicated in several diseases, including Carney-Stratakis syndrome; gastrointestinal stromal tumor; and paraganglioma. Is an ortholog of human SDHC (succinate dehydrogenase complex subunit C).