Acts as a mitochondrial iron-sulfur (Fe-S) cluster assembly factor that facilitates (Fe-S) cluster insertion into a subset of mitochondrial proteins (By similarity). Probably acts together with the monothiol glutaredoxin GLRX5 (PubMed:27532772). May protect cells against oxidative stress (PubMed:22746225). Interacts with GLRX5 (PubMed:22746225, PubMed:27532773, PubMed:27532772). Widely expressed. Belongs to the BolA/IbaG family. Was initially reported to be secreted via a non-classical export pathway (PubMed:18548201). It was however later shown that it localizes to mitochondria, in agreement with other members of the family (PubMed:22746225).