| Popis: |
The coiled-coil motif mediates subunit oligomerization and scaffolding, and underlies several fundamental biologic processes. Prohibitins (PHBs), mitochondrial inner membrane proteins involved in mitochondrial homeostasis and signal transduction, are predicted to have a coiled-coil motif, but their structural features are poorly understood. Here we solved the crystal structure of the heptad repeat (HR) region of PHB2 at 1.7 A resolution. It assembles into a dimeric, antiparallel coiled-coil with a unique negatively charged area essential for the PHB interactome in mitochondria. Disruption of the HR coiled-coil prevents well-ordered PHB complexes and abolishes mitochondrial tubular networks. We found that PHB2 associated with a caseinolytic peptidase B protein homolog, also known as mitochondrial ATPase associated with diverse cellular activities ATPase chaperonin, via a coiled-coil, thereby ensuring mitochondrial-mediated antiviral innate immunity. Elucidation of the PHB complex structure in mitochondria provides insight into essential PHB interactomes required for mitochondrial dynamics as well as cellular signal transduction. |
