Enables succinate dehydrogenase (ubiquinone) activity. Involved in respiratory electron transport chain and succinate metabolic process. Located in mitochondrial inner membrane. Human ortholog(s) of this gene implicated in Leigh disease; dilated cardiomyopathy 1GG; lung non-small cell carcinoma; mitochondrial complex II deficiency; and paraganglioma. Orthologous to human SDHA (succinate dehydrogenase complex flavoprotein subunit A). [provided by Alliance of Genome Resources, Apr 2022]