Figure 5. Mutational analysis of charged amino acids from the α-helices of CBS1 and CBS2 domains.

A, a detailed view of the helices from a homology model of the CBS1 domain of ClC-1, showing the amino acids that had been mutated and analysed functionally in oocytes. Amino acids from the first α-helix are shown in green, and from the second α-helix in pink. Right panel, values of the half-voltage of activation (V_0.5) for mutants in the helices of the CBS1 domain of ClC-1 as determined by tail current analysis (see Methods). Experimental conditions were as in Fig. 4E. The dashed line corresponds to the value of the wild-type ClC-1. B, an analysis as in A of the CBS2 domain of ClC-1. Mutations that caused a deviation of V_0.5 of more than 10 mV with respect to the wild-type value are marked in red.