E-G. Assessment of the model-map fit. Upper panels show single DC domains bound to four tubulin subunits: t, MT polymerization time; density maps, semi-transparent isosurface; models, backbone. Lower panels show close-up views of the MT-facing side of the DC domains (backbone + side chains shown as sticks). The main differentiating features between NDC and CDC are highlighted with dashed lines. NDC density in the NN reconstruction (G) results from averaging of two NDCs with varying N-terminal region, causing less defined density for that region (N-term scrambling, shown without side chains). Colouring as in (C). 