In yeast (Saccharomyces cerevisiae) and animals, the sulfhydryl oxidase Erv1 functions with Mia40 in the import and oxidative folding of numerous cysteine-rich proteins in the mitochondrial intermembrane space (IMS). Erv1 is also required for Fe-S cluster assembly in the cytosol, which uses at least one mitochondrially derived precursor. Here, we characterize an essential Erv1 orthologue from the protist Trypanosoma brucei (TbERV1), which naturally lacks a Mia40 homolog. We report kinetic parameters for physiologically relevant oxidants cytochrome c and O(2), unexpectedly find O(2) and cytochrome c are reduced simultaneously, and demonstrate that efficient reduction of O(2) by TbERV1 is not dependent upon a simple O(2) channel defined by conserved histidine and tyrosine residues. Massive mitochondrial swelling following TbERV1 RNA interference (RNAi) provides evidence that trypanosome Erv1 functions in IMS protein import despite the natural absence of the key player in the yeast and animal import pathways, Mia40. This suggests significant evolutionary divergence from a recently established paradigm in mitochondrial cell biology. Phylogenomic profiling of genes also points to a conserved role for TbERV1 in cytosolic Fe-S cluster assembly. Conversely, loss of genes implicated in precursor delivery for cytosolic Fe-S assembly in Entamoeba, Trichomonas, and Giardia suggests fundamental differences in intracellular trafficking pathways for activated iron or sulfur species in anaerobic versus aerobic eukaryotes.

• MeSH
• cytochromy c chemie   MeSH
• fylogeneze MeSH
• genový knockdown MeSH
• kinetika MeSH
• kyslík chemie   MeSH
• mitochondriální proteiny chemie   genetika   MeSH
• mitochondrie enzymologie   ultrastruktura   MeSH
• molekulární evoluce MeSH
• mutageneze cílená MeSH
• oxidace-redukce MeSH
• oxidancia MeSH
• oxidoreduktasy chemie   genetika   MeSH
• protozoální proteiny chemie   genetika   MeSH
• RNA interference MeSH
• sbalování proteinů MeSH
• substituce aminokyselin MeSH
• transport proteinů MeSH
• Trypanosoma brucei brucei cytologie   enzymologie   MeSH
• zduření mitochondrií MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• cytochromy c MeSH
• kyslík MeSH
• mitochondriální proteiny MeSH
• oxidancia MeSH
• oxidoreduktasy MeSH
• protozoální proteiny MeSH
• sulfhydryl oxidase MeSH Prohlížeč