The large conductance mechanosensitive channel (MscL), acts as an osmoprotective
emergency valve in bacteria by opening a large, water-filled pore in response to changes in
membrane tension. In its closed configuration, the last 36 residues at the C-terminus form a
bundle of five α-helices co-linear with the five-fold axis of symmetry. Here, we examined the
structural dynamics of the C-terminus of EcMscL using site-directed spin labelling electron
paramagnetic resonance (SDSL EPR) spectroscopy. These experiments were …

The large conductance mechanosensitive channel (MscL), acts as an osmoprotective
emergency valve in bacteria that gates in response to membrane tension to open a large,
water-filled pore of∼ 30 Å in diameter. In its closed configuration, the last 36 residues at the
C-terminus form a bundle of five α-helices co-linear with the five-fold axis of symmetry.
However, the physiological relevance of this bundle has been put in doubt given the
unorthodox crystallographic conditions (pH 3.6-3.8). To resolve the controversy, we …