Susume Lv 1
Baker lab has designed some beautiful self-assembling nanocages made up of solenoid proteins. This nanocage is a tetrahedron, where each of the four vertices is a trimer of beta helices: https://www.rcsb.org/3d-view/4DCL/1
In the 3D viewer, if you click the 3-dot menu next to Polymer, set coloring, polymer chain instance, it will paint each monomer a different color to make them easier to see.
Here is a beta helix from Baker lab with both parallel sheets and alpha helices: https://www.rcsb.org/3d-view/4R5D
They have also designed all-helix solenoids, like this one: https://www.rcsb.org/3d-view/5BYO
The associated paper has some images showing how they assemble and how they pack: https://www.bakerlab.org/wp-content/uploads/2015/12/Doyle_Nature_2015.pdf
Here is a synthetic solenoid with square cross-section from another lab: https://www.rcsb.org/3d-view/4YC5
