Member of gene cluster sufABCDSE that mediates iron-sulfur cluster assembly under oxidative stress and iron limitation conditions (PubMed:17941825). Binds [2Fe2S] cluster by mobilizing sulfur atoms provided by the SufS-SufE cysteine desulfurase system and then transfers the assembled Fe-S cluster to target proteins including ferredoxin and aconitase (PubMed:17350000, PubMed:19366265). Seems to act as a Fe-S cluster carrier rather than a scaffold, this role being performed by SufB and SufC (PubMed:19810706, PubMed:23018275). Homodimer (PubMed:16298366). Interacts with SufB and SufC (PubMed:19810706). Deletion has only a mild effect on cell growth (PubMed:17941825). However, deletion of both IscA and SufA results in a severe growth phenotype in minimal medium under aerobic growth conditions (PubMed:17941825). Belongs to the HesB/IscA family.