Nanobiotechnology of protein-based compartments: steps toward nanofactories

Nanobiotechnology of toroids/donuts, yoctowells, tubes, cages, capsids, compartments and organelles based on protein-building blocks allows for the definition of precise reaction spaces in vitro and in vivo. Utilizing a synthetic biology approach, the generation of compartment-forming protein ‘bio-bricks’ points toward new ways to control the assembly of these structures to develop nanofactories in vivo. This is envisioned to be an important step allowing for the precise assembly of novel metabolic cascades within nanoreactors in the future. The ability to site-selectively modify proteins by inserting or replacing selected natural and unnatural amino acids at defined positions, provides the necessary tools to control novel functions via ‘genetic programming’. The protein-building blocks, already embedded in nature's nanocompartment tool box, will be the focus of this review. The various protein structures forming compartments in vitro and in vivo will be presented together with their current applications.