Iron Sulfur Cluster Assembly 2 (ISCA2)

IscA2 exists as a protein complex with the HEAT-repeat-containing protein. The absorption spectrum of the recombinant IscA2/IaiH complex resembles that of IscA2 alone, although it is sharper.

When any one of three conserved cysteine residues in IscA2, potential ligands for the [2Fe-2S] cluster, was replaced with serine, the amount of assembled [2Fe-2S] cluster and protein complex was significantly reduced in E. coli cells. The cysteine mutated IscA2/IaiH complexes that were present all contained a [2Fe-2S]-like cluster suggesting that the assembly of a stable iron-sulfur cluster bound to IscA2 is required for efficient and stable complex formation. Truncated IaiH proteins were analyzed using the yeast two-hybrid assay to identify the essential domain of IaiH that interacts physically with IscA2.