The SufBCD Fe-S Scaffold Complex Interacts with SufA for Fe-S Cluster Transfer

Iron-sulfur clusters are key iron cofactors in biological pathways ranging from nitrogen fixation to respiration Because of the toxicity Of ferrous iron and sulfide to the cell, in vivo Fe-S cluster assembly transpires via multiprotein biosynthetic pathways. Fe-S cluster assembly proteins traffic iron and sulfide: assemble nascent Fe-S clusters, and correctly transfer Fe-S Clusters to the appropriate target metalloproteins in Vivo The Gram-negative bacterium Escherichia coli contains it stress-responsive Fe-S cluster assembly system, the SufABCDSE pathway, that functions under iron starvation and oxidative stress conditions that compromise Fe-S homeostasis. Using it combination of protein-protein interaction and in vitro Fe-S cluster assembly assays. we have characterized the relative roles or the SufBCD complex and the SufA protein during Suf Fe-s cluster biosynthesis. These studies reveal that SLIM interacts with SufBCD to accept Fe-S Clusters formed de novo oil the SufBCD complex Our results represent the first biochemical evidence that the SufBCD complex within the Suf pathway Functions as a novel Fe-S scaffold system to assemble nascent Clusters and transfer them to the SufA Fe-S shuttle