Fe-S protein assembly and DNA repair

Iron-sulfur (Fe-S) clusters are ancient inorganic protein cofactors of vast functional diversity. Found across all three domains of life, Fe-S clusters play key roles essential for life ranging from electron transfer, chemical catalysis, sensing of cellular oxygen and iron levels, to stabilizing protein folds. In eukaryotic cells, Fe-S clusters are not only found in mitochondrial respiratory chain complexes, but they are also essential cofactors for the cytosolic and nuclear proteome. In particular, Fe-S clusters are essential components of many proteins involved in DNA replication and DNA repair. While Fe-S clusters are essential for the functions of these DNA metabolism proteins, and pathological mutations in the Fe-S domains of XPD, FANCJ, RTEL1 and DDX11 are the underlying causes of trichothiodystrophy, Fanconi anemia, dyskeratosis congenita, and Warsaw breakage syndrome, respectively, the precise roles of their Fe-S clusters remain enigmatic. Given the cellular toxicity of free iron, the biogenesis of Fe-S proteins requires a tightly regulated, multi-step process, which has been highly conserved throughout evolution and relies on dedicated machineries in the specific cellular compartments. 

Our research aims to obtain a detailed mechanistic understanding of the cellular pathways required for eukaryotic Fe-S protein assembly, and the functions and molecular mechanisms of Fe-S proteins involved in DNA repair. We use an integrative approach employing in vitro biochemical reconstitution, biophysical methods, and structural analyses by X-ray crystallography and cryo-electron microscopy, to shed light on the mechanisms underpinning the maturation of Fe-S proteins, including critical DNA repair enzymes.