Fig. 1.

Molecular structure of CFTR. a Cartoon of the CFTR protein showing the location and charge of the all amino acids mutated in this study. Note that the extracellular loops are not drawn to scale. b Three-dimensional homology model of CFTR based on the work of Dalton et al. [14], using PyMol software indicating the relative positions of R899, W401 and E1371 residues to other regions of note. Note that the homology model lacks the R domain and that in the right hand diagram, the extracellular surface of CFTR is orientated to face the reader.