Figure 1.

(a) Integrative 3D model of a mature insulin secretory granule. One quadrant is clipped away to show the insulin crystal (turquoise). The long coiled-coil proteins in green are granins, and the lumen is dominated by many copies of the small beta-peptide left over from the maturation of insulin. (b) Structural proteomes used to build the models. Cytoplasmic proteins are at the top in red and magenta, vesicle membrane-spanning and membrane-associated proteins are at the centre in orange and yellow-green and vesicle lumen proteins are at the bottom in blue-green.