A dynamic displacement mechanism drives protein import into mitochondria

A conserved short linear motif in the cytosolic Tom22 domain forms a transient -helical PPDE that displaces preproteins above the TOM pore to drive outer-membrane import.

• Why it matters: The handoff from cytosolic receptor domains to the TOM translocation pore is not explained by existing TOM structures, leaving the transfer mechanism unclear.
• What they did: Using atomic-level structural techniques plus in vivo experiments, the study identified a transient -helical element in disordered Tom22 and tested its competitive binding to Tom20 and Tom70 precursor sites.
• The result: The PPDE interaction facilitates release of preproteins directly above the import pore, implying that flexibility—not rigid scaffolding—enables efficient ligand displacement during mitochondrial protein translocation.

AI summary of the abstract · may contain errors · not medical advice · read the paper.