(a) Cartoon of fused-domain construct, showing numbered transmembrane helices in Ec2 domains (open) fused by an 'inversion linker' containing a non-dimerizing glycophorin A helix (grey). (b) Coomassie-stained SDS PAGE gel of purified Ec2 homodimer (left lane) and concatemer (right lane), with soluble-marker ladder positions indicated. (c) Representative F− efflux traces of indicated concatemeric constructs. (d) Representative single-channel recordings in the presence of 75–150 nM monobody, which induces long-lived nonconducting 'blocked' intervals; conducting intervals in these traces represent times when channels are free of monobody, with intrinsic open probability >95% (Stockbridge et al., 2014). Grey lines represent blocked current level.
DOI:
http://dx.doi.org/10.7554/eLife.18767.005