Monothiol glutaredoxin involved in mitochondrial iron-sulfur (Fe/S) cluster transfer (PubMed:11950925, PubMed:12730244, PubMed:23615440). Receives 2Fe/2S clusters from scaffold protein ISU1 and mediates their transfer to apoproteins, to the 4Fe/FS cluster biosynthesis machinery, or export from mitochondrion (PubMed:27532773, PubMed:23615440). E(0) is -175 mV. Homodimer (By similarity). Interacts with SSQ1 (PubMed:23615440). Interacts with BOL1 (PubMed:27532773). Present with 6260 molecules/cell in log phase SD medium. Belongs to the glutaredoxin family. Monothiol subfamily.