MIA40, found in the mitochondrial intermembrane space, is a central component in the import system that transports certain cysteine motif–containing proteins into the mitochondria. New analyses reveal that MIA40 forms a novel thioredoxin fold. Its redox center catalyzes the formation of the first disulfide bond of a substrate, causing the susbtrate's second disulfide to require only oxygen for its formation.
- Lucia Banci
- Ivano Bertini
- Kostas Tokatlidis
