4QCC: Structure Of A Cube-shaped, Highly Porous Protein Cage Designed By Fusing Symmetric Oligomeric Domains

Natural proteins can be versatile building blocks for multimeric, self-assembling structures. Yet, creating protein-based assemblies with specific geometries and chemical properties remains challenging. Highly porous materials represent particularly interesting targets for designed assembly. Here, we utilize a strategy of fusing two natural protein oligomers using a continuous alpha-helical linker to design a novel protein that self assembles into a 750 kDa, 225 A diameter, cube-shaped cage with large openings into a 130 A diameter inner cavity. A crystal structure of the cage showed atomic-level agreement with the designed model, while electron microscopy, native mass spectrometry and small angle X-ray scattering revealed alternative assembly forms in solution. These studies show that accurate design of large porous assemblies with specific shapes is feasible, while further specificity improvements will probably require limiting flexibility to select against alternative forms. These results provide a foundation for the design of advanced materials with applications in bionanotechnology, nanomedicine and material sciences.
PDB ID: 4QCCDownload
MMDB ID: 124868
PDB Deposition Date: 2014/5/10
Updated in MMDB: 2014/12
Experimental Method:
x-ray diffraction
Resolution: 7.08  Å
Source Organism:
Similar Structures:
Biological Unit for 4QCC: 24-meric; determined by author and by software (PISA)
Molecular Components in 4QCC
Label Count Molecule
Proteins (24 molecules)
2-dehydro-3-deoxy-6-phosphogalactonate Aldolase, Peptidyl- Prolyl Cis-trans Isomerase Chimera(Gene symbol: dgoA)
Molecule annotation
* Click molecule labels to explore molecular sequence information.

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