Nar1p, a conserved eukaryotic protein with similarity to Fe-only hydrogenases, functions in cytosolic iron-sulphur protein biogenesis.
The genome of the yeast Saccharomyces cerevisiae encodes the essential protein Nar1p that is conserved in virtually all eukaryotes and exhibits striking sequence similarity to bacterial iron-only hydrogenases. Previously, we have shown that Nar1p is an Fe-S protein and that assembly of its co-factors depends on the mitochondrial Fe-S cluster biosynthesis apparatus. Using functional studies in vivo, we demonstrated that Nar1p has an essential role in the maturation of cytosolic and nuclear, but not of mitochondrial, Fe-S proteins. Here we provide further spectroscopic evidence that Nar1p possesses two Fe-S clusters. We also show that Nar1p is required for Fe-S cluster assembly on the P-loop NTPase Nbp35p, another newly identified component of the cytosolic Fe-S protein assembly machinery. These data suggest a complex biochemical pathway of extra-mitochondrial Fe-S protein biogenesis involving unique eukaryotic proteins.
Balk
J
J
Institut für Zytobiologie und Zytopathologie, Philipps-Universität Marburg, Robert-Koch-Strasse 6, D-35033 Marburg, Germany.
Pierik
A J
AJ
Aguilar Netz
D J
DJ
Mühlenhoff
U
U
Lill
R
R
D020418:Algal Proteins / Q000378:metabolism / Q000502:physiology*; D027321:Anion Transport Proteins / Q000378:metabolism / Q000502:physiology*; D003600:Cytosol / Q000378:metabolism*; D004578:Electron Spin Resonance Spectroscopy; D006864:Hydrogenase / Q000378:metabolism*; D007506:Iron-Sulfur Proteins / Q000096:biosynthesis* / Q000378:metabolism*; D010957:Plasmids
D020418:Algal Proteins; D027321:Anion Transport Proteins; D007506:Iron-Sulfur Proteins; C118830:iron hydrogenase; D006864:Hydrogenase