Cysteine desulfurase (tRNA sulfurtransferase), PLP-dependent; Master enzyme that delivers sulfur to a number of partners involved in Fe-S cluster assembly, tRNA modification or cofactor biosynthesis. Catalyzes the removal of elemental sulfur from cysteine to produce alanine. Functions as a sulfur delivery protein for Fe-S cluster synthesis onto IscU, an Fe-S scaffold assembly protein, as well as other S acceptor proteins. Preferentially binds to disordered IscU on which the Fe-S is assembled, IscU converts to the structured state and then dissociates from IscS to transfer the Fe-S to a [...]

HscA co-chaperone, J domain-containing protein Hsc56; Co-chaperone involved in the maturation of iron-sulfur cluster-containing proteins. Seems to help targeting proteins to be folded toward HscA; Belongs to the HscB family.

FeS cluster assembly protein; Is able to transfer iron-sulfur clusters to apo-ferredoxin. Multiple cycles of [2Fe2S] cluster formation and transfer are observed, suggesting that IscA acts catalytically. Recruits intracellular free iron so as to provide iron for the assembly of transient iron-sulfur cluster in IscU in the presence of IscS, L-cysteine and the thioredoxin reductase system TrxA/TrxB; Belongs to the HesB/IscA family.

DnaK-like molecular chaperone specific for IscU; Chaperone involved in the maturation of iron-sulfur cluster- containing proteins. Has a low intrinsic ATPase activity which is markedly stimulated by HscB. Involved in the maturation of IscU; Belongs to the heat shock protein 70 family.

[2Fe-2S] ferredoxin; Ferredoxin are iron-sulfur proteins that transfer electrons in a wide variety of metabolic reactions. Although the function of this ferredoxin is unknown it is probable that it has a role as a cellular electron transfer protein. Involved in the in vivo assembly of the Fe-S clusters in a wide variety of iron-sulfur proteins.

Fe(2+) donor and activity modulator for cysteine desulfurase; May function as iron donor in the assembly of iron-sulfur clusters; Belongs to the IscX family.

Fe/S biogenesis protein, putative scaffold/chaperone protein; Involved in iron-sulfur cluster biogenesis under severe conditions such as iron starvation or oxidative stress. Binds a 4Fe-4S cluster, can transfer this cluster to apoproteins, and thereby intervenes in the maturation of Fe/S proteins. Could also act as a scaffold/chaperone for damaged Fe/S proteins. Required for E.coli to sustain oxidative stress and iron starvation. Also necessary for the use of extracellular DNA as the sole source of carbon and energy. Belongs to the NfuA family.

Iron-sulfur cluster insertion protein; Probably involved in the insertion of Fe-S clusters into apoproteins in vivo including IspG and/or IspH. Essential for growth under aerobic conditions and for anaerobic respiration but not for fermentation. In vitro it binds Fe-S clusters and transfers them to apo-IspG, which is involved in quinone biosynthesis among many other cell components. Experiments indicate that it is probably also involved in the insertion of other Fe-S clusters than IspG/IspH; Belongs to the HesB/IscA family.

Redox-sensitive transcriptional activator of soxS; Activates the transcription of the soxS gene which itself controls the superoxide response regulon. SoxR contains a 2Fe-2S iron- sulfur cluster that may act as a redox sensor system that recognizes superoxide. The variable redox state of the Fe-S cluster is employed in vivo to modulate the transcriptional activity of SoxR in response to specific types of oxidative stress. Upon reduction of 2Fe-2S cluster, SoxR reversibly loses its transcriptional activity, but retains its DNA binding affinity.