Acts as a cytosolic iron-sulfur (Fe-S) cluster assembly factor that facilitates [2Fe-2S] cluster insertion into a subset of cytosolic proteins. Acts together with the monothiol glutaredoxin GLRX3. Interacts with GLRX3; forms a heterotrimeric complex composed by two BOLA2 molecules and one GLRX3 molecule; linked by [2Fe-2S] clusters. Belongs to the BolA/IbaG family.