Fig. S1.

The resolution of the reconstruction has been estimated using FSC comparisons (A) between the map and the refined atomic model and (B) between two half-maps generated from independent nonoverlapping datasets. (A) The blue curve is from the comparison between the model and the full map (including the region containing 61 residues where no model has been built), whereas the red curve is from masking off both the model and the map, so that only the α-helical core is being compared. The vertical line suggests that the overall reconstruction is somewhat worse than 4.0 Å, whereas the inner core is somewhat better than 4.0 Å. In B, no masking of the poorly ordered outer region has been done, and the overall resolution using an FSC = 0.143 criterion is 4.3 Å.