+1 Recommend
0 collections
      • Record: found
      • Abstract: found
      • Article: not found

      Mim1 functions in an oligomeric form to facilitate the integration of Tom20 into the mitochondrial outer membrane.

      Journal of Molecular Biology

      metabolism, genetics, chemistry, Schizosaccharomyces, Saccharomyces cerevisiae Proteins, Saccharomyces cerevisiae, Receptors, Cytoplasmic and Nuclear, Protein Structure, Tertiary, Neurospora crassa, Mitochondrial Membranes, Mitochondrial Membrane Transport Proteins, Membrane Proteins, Dimerization

      Read this article at

          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.


          The translocase of the outer mitochondrial membrane (TOM) complex is the general entry site into the organelle for newly synthesized proteins. Despite its central role in the biogenesis of mitochondria, the assembly process of this complex is not completely understood. Mim1 (mitochondrial import protein 1) is a mitochondrial outer membrane protein with an undefined role in the assembly of the TOM complex. The protein is composed of an N-terminal cytosolic domain, a central putative transmembrane segment (TMS) and a C-terminal domain facing the intermembrane space. Here we show that Mim1 is required for the integration of the import receptor Tom20 into the outer membrane. We further investigated what the structural characteristics allowing Mim1 to fulfil its function are. The N- and C-terminal domains of Mim1 are crucial neither for the function of the protein nor for its biogenesis. Thus, the TMS of Mim1 is the minimal functional domain of the protein. We show that Mim1 forms homo-oligomeric structures via its TMS, which contains two helix-dimerization GXXXG motifs. Mim1 with mutated GXXXG motifs did not form oligomeric structures and was inactive. With all these data taken together, we propose that the homo-oligomerization of Mim1 allows it to fulfil its function in promoting the integration of Tom20 into the mitochondrial outer membrane.

          Related collections

          Author and article information



          Comment on this article