Involved in the mitochondrial activation of SOD2 by specifically facilitating insertion of the essential manganese cofactor. Has the ability to activate iron regulon in an iron-dependent manner. Responds to calorie restriction (CR) strength. Loss of mitochondrial manganese superoxide dismutase SOD2 activity due to misincorporation of iron into SOD2 rather than manganese. Normal SOD2 activity when in association with YFH1 deletion. Doesn't impair activity of a cytosolic version of manganese SOD. The iron regulatory transcription factor AFT1 is constitutively active. Accumulates mtDNA mutations. Elevated mitochondrial iron and manganese levels. Present with 538 molecules/cell in log phase SD medium. Belongs to the mitochondrial carrier (TC 2.A.29) family.