Translocase of the Outer Membrane (TOM complex) of hydrogenosomes in Trichomonas vaginalis

Mitochondria originated from α-proteobacterial endosymbionts, and the endosymbiont-to-organelle transition is tightly linked to the establishment of protein import pathways. The initial import of most proteins is mediated by the translocase of the outer membrane (TOM). Although TOM is common to all forms of mitochondria, recent studies have shown diversity of TOM subunits between main eukaryotic lineages. However, experimental knowledge is currently limited to a few model organisms. Here, we analysed the TvTOM complex in hydrogenosomes, an anaerobic form of mitochondria found in the excavate Trichomonas vaginalis. Using the pore-forming TvTom40-2 as bait, we immunoprecipitated the high molecular weight TvTOM complex both under crosslinking and native conditions and performed label-free quantitative mass spectrometry (LFQ-MS) to identify the components of the TvTOM complex. Further, we used two proteins that were enriched, Homp36 and Sam50 as baits for reciprocal experiments.