Figure 1.

Schema of the main steps of Fe-S protein maturation. Only the mitochondrial ISC machinery components are detailed. Mitoferrin (MFRN) is involved in iron entry in mitochondria. Proteins in yellow frames are needed for cysteine desulfuration and [2Fe-2S] cluster de novo assembly on the ISCU. After its transfer on GLRX5, the [2Fe-2S] cluster is exported to the cytosol (for extra-mitochondrial Fe-S protein maturation) and is inserted to mitochondrial [2Fe-2S] proteins or is taken in charge by proteins essential for [4Fe-4S] cluster biosynthesis and the maturation of mitochondrial [4Fe-4S] containing proteins. Proteins involved in MMDS pathologies are framed in red.