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A novel eukaryotic factor for cytosolic Fe–S cluster assembly
Author(s) -
Roy Amit,
Solodovnikova Natalia,
Nicholson Tracy,
Antholine William,
Walden William E.
Publication year - 2003
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1093/emboj/cdg455
Subject(s) - aconitase , cytosol , saccharomyces cerevisiae , cytoplasm , yeast , iron–sulfur cluster , gene , biochemistry , biology , chemistry , mitochondrion , microbiology and biotechnology , genetics , enzyme
Iron regulatory protein 1 (IRP1) is regulated through the assembly/disassembly of a [4Fe–4S] cluster, which interconverts IRP1 with cytosolic aconitase. A genetic screen to isolate Saccharomyces cerevisiae strains bearing mutations in genes required for the conversion of IRP1 to c‐aconitase led to the identification of a previously uncharacterized, essential gene, which we call CFD1 ( c ytosolic F e–S cluster d eficient). CFD1 encodes a highly conserved, putative P‐loop ATPase. A non‐lethal mutation of CFD1 ( cfd1‐1 ) reduced c‐aconitase specific activity in IRP1‐transformed yeast by >90%, although IRP1 in these cells could be readily converted to c‐aconitase in vitro upon incubation with iron alone. IRP1‐transformed cfd1‐1 yeast lacked EPR‐detectable Fe–S clusters in c‐aconitase, pointing to a defect in Fe–S cluster assembly. The specific activity of another cytosolic Fe–S protein, Leu1p, was also inhibited by >90% in cfd1‐1 yeast, whereas activity of mitochondrial Fe–S proteins was not inhibited. Consistent with a cytosolic site of activity, Cfd1p was localized in the cytoplasm. To our knowledge, Cfd1p is the first cytoplasmic Fe–S cluster assembly factor described in eukaryotes.