InterPro domain: IPR000361

The proteins in this entry are variously annotated as iron-sulphur cluster insertion protein or Fe/S biogenesis protein. They appear to be involved in Fe-S cluster biogenesis. This family includes IscA, HesB, YadR and YfhF-like proteins. The hesB gene is expressed only under nitrogen fixation conditions [ 1 ]. IscA, an 11kDa member of the hesB family of proteins, binds iron and [2Fe-2S] clusters, and participates in the biosynthesis of iron-sulphur proteins. IscA is able to bind at least 2 iron ions per dimer [ 2 ]. Other members of this family include various hypothetical proteins that also contain the NifU-like domain ( IPR001075 ) suggesting that they too are able to bind iron and are involved in Fe-S cluster biogenesis. The HesB family are found in species as divergent as Homo sapiens (Human) and Haemophilus influenzae suggesting that these proteins are involved in basic cellular functions [ 3 ].

1. Organization and expression of nitrogen-fixation genes in the aerobic nitrogen-fixing unicellular cyanobacterium Synechococcus sp. strain RF-1. Microbiology (Reading, Engl.) 145 ( Pt 3), 743-53
2. Crystal structure of IscA, an iron-sulfur cluster assembly protein from Escherichia coli. J. Mol. Biol. 338, 127-37
3. A modular domain of NifU, a nitrogen fixation cluster protein, is highly conserved in evolution. J. Mol. Evol. 43, 536-40