TOM22

TgTom22 is a Toxoplasma gondii homologue of Tom22 that serves as a central component of the translocon of the outer mitochondrial membrane (TOM) complex (PMID:27458014). Loss-of-function analysis establishes that it is essential for parasite survival, required for mitochondrial protein import, and necessary for assembly of the TOM complex (PMID:27458014). Beyond (PMID:27458014), no further mechanistic detail — including its receptor topology, direct precursor-binding partners, or biochemical interactions within the TOM complex — has been characterized in the available corpus.

1. 2016 Medium

   Whether Toxoplasma possesses a functional Tom22-like TOM component and whether it is dispensable was unknown; loss-of-function analysis showed TgTom22 is essential and required for both mitochondrial protein import and TOM complex assembly, establishing it as a core, non-redundant component of the parasite import machinery.

   Evidence Loss-of-function genetic analysis with parasite survival, mitochondrial protein import, and TOM complex assembly readouts in T. gondii

   PMID:27458014

   Open questions at the time

   • No structural or topological model of TgTom22 within the TOM complex
   • Direct precursor- or receptor-binding partners not identified
   • Single study from a single lab without reciprocal biochemical validation

• How TgTom22 recognizes and hands off imported precursors, its interactions with other TOM subunits, and its molecular architecture remain undefined.
• No identified substrate or precursor-binding activity
• No defined interactions with specific TOM subunits
• No structural characterization