Fig. 4: NSS-loop conformations.

a Concentric circles of NSS-loops. Conformations in the CDTa-bound state are shown without (left) or with (right) the CDTa N-terminal domain. ‘in’ loop conformations are shown in blue, ‘out’ conformations in yellow. b Cryo-EM map of NSS-loops of the CDTb-pore in the CDTa-bound state without (left) or with (right) the CDTa N-terminal domain. c The close-up views of ‘in’ and ‘out’ conformations of subunits A–G.