Figure 3.

Various combinations of β-propellers with α-helical stack domains. Sequence comparison and structure prediction methods have revealed that many scaffolding proteins in the NPC, in vesicle coats and elsewhere, are built up from β-propeller domains combined, in cis or in trans, with α-helical stacks. Four examples of architectural proteins are given and drawn to scale. Although β-propellers (orange) do not structurally diverge drastically and can generally be superimposed well, α-helical stack domains (in blue–white color gradient) can adopt many shapes.