Component of the MIM complex required for mitochondrial outer membrane protein import (PubMed:22467864). The MIM complex cooperates with the receptor TOM70 in binding of precursor proteins and promotes their insertion and assembly into the outer membrane (PubMed:21825073). Involved in import of the subset of proteins with multiple alpha-helical transmembrane segments, including UGO1 (PubMed:21825073, PubMed:21825074). Required for the assembly of the TOM (translocase of outer membrane) receptor complex, which is responsible for the recognition and translocation of cytosolically synthesized mitochondrial preproteins (PubMed:15242642, PubMed:15326197, PubMed:15608614). Required specifically for assembly of TOM40, TOM20, and TOM70, but not TOM22 (PubMed:17974559, PubMed:18187149). Component of the MIM complex containing at least MIM1 and MIM2 (PubMed:15608614, PubMed:18187149, PubMed:21825073, PubMed:22467864). Interacts with MIM2; interaction is direct (PubMed:22467864). Interacts with TOM70 (PubMed:21825073). Leads to reduced levels of TOM complex but retains the respiratory chain. Belongs to the MIM1 family.