The function of Mim1 in the biogenesis of the mitochondrial TOM complex

The translocase of the outer mitochondrial membrane (TOM complex) is the general entry site for newly synthesized proteins into the organelle. The translocase is a multi-subunit complex composed of seven subunits: two receptor proteins, Tom70 and Tom20, and five components which form the core complex, Tom40, Tom22, Tom7, Tom6, and Tom5. In this thesis it is shown that Mim1 is required for the integration of the import receptor Tom20 into the outer membrane but not for its assembly into the TOM complex. Structural characteristics of Mim1 required for its function were studied in detail. Mim1 forms homooligomeric structures via its transmembrane segment which contains two helix-dimerization GXXXG/A motifs. The homooligomerization is a precondition for the function of Mim1 in mediating the integration of Tom20 into the mitochondrial outer membrane.