Quinone-trapping filaments enhance respiratory capacity.

Hollow protein filaments in Bacillus subtilis extend respiratory capacity by sequestering quinones without membrane addition, revealing an alternative bioenergetic expansion route.

• Why it matters: Understanding how cells increase respiratory capacity is crucial for insights into bioenergetics and bacterial adaptability. The typical method involves membrane expansion, but alternative strategies remain underexplored.
• What they did: Kropp and colleagues identified that Bacillus subtilis builds hollow protein filaments that sequester and transport quinones, a process observed across Bacillota, providing a membrane-independent means to enhance respiration.
• The result: This discovery suggests that filament-based quinone transport may be a widespread strategy among Bacillota, potentially enabling bacteria to expand respiratory capacity without membrane proliferation.