Homologous Superfamily

IscX-like superfamily (IPR036762)

Short name: IscX-like_sf

Overlapping entries


The ISC system is conserved in eubacteria and eukaryotes (mitochondria), and has broad specificity, targeting general FeS proteins [PMID: 16211402, PMID: 16843540]. It is encoded by the isc operon (iscRSUA-hscBA-fdx-iscX). IscS is a cysteine desulphurase, which obtains S from cysteine (converting it to alanine) and serves as a S donor for FeS cluster assembly. IscU and IscA act as scaffolds to accept S and Fe atoms, assembling clusters and transfering them to recipient apoproteins. HscA is a molecular chaperone and HscB is a co-chaperone. Fdx is a [2Fe-2S]-type ferredoxin. IscR is a transcription factor that regulates expression of the isc operon. IscX (also known as YfhJ) appears to interact with IscS and may function as an Fe donor during cluster assembly [PMID: 15937904].

This entry represents IscX proteins (also known as hypothetical protein YfhJ) that are part of the ISC system. IscX is active as a monomer. The structure of YfhJ is an orthogonal alpha-bundle [PMID: 15937904]. YfhJ is a small acidic protein that binds IscS, and contains a modified winged helix motif that is usually found in DNA-binding proteins [PMID: 16698547]. YfhJ/IscX can bind Fe, and may function as an Fe donor in the assembly of FeS clusters

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.