Paper Citing NAMD - Abstract
Wang, Yong; Liu, Yanxin; DeBerg, Hannah A.; Nomura, Takeshi; Hoffman, Melinda Tonks; Rohde, Paul R.; Schulten, Klaus; Martinac, Boris; Selvin, Paul R.
Single molecule FRET reveals pore size and opening mechanism of a mechano-sensitive ion channel
ELIFE, 3 Art. No. e01834, FEB 18 2014
The mechanosensitive channel of large conductance, which serves as a model system for mechanosensitive channels, has previously been crystallized in the closed form, but not in the open form. Ensemble measurements and electrophysiological sieving experiments show that the open-diameter of the channel pore is >25 angstrom, but the exact size and whether the conformational change follows a helix-tilt or barrel-stave model are unclear. Here we report measurements of the distance changes on liposome-reconstituted MscL transmembrane a-helices, using a 'virtual sorting' single-molecule fluorescence energy transfer. We observed directly that the channel opens via the helix-tilt model and the open pore reaches 2.8 nm in diameter. In addition, based on the measurements, we developed a molecular dynamics model of the channel structure in the open state which confirms our direct observations.
