Premium
Metal‐dependent assembly of a protein nano‐cage
Author(s) -
CristieDavid Ajitha S.,
Marsh E. Neil G.
Publication year - 2019
Publication title -
protein science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.353
H-Index - 175
eISSN - 1469-896X
pISSN - 0961-8368
DOI - 10.1002/pro.3676
Subject(s) - crystallography , ethylenediaminetetraacetic acid , metal , metal ions in aqueous solution , coiled coil , chemistry , monomer , protein structure , self assembly , globular protein , protein design , biochemistry , inorganic chemistry , chelation , organic chemistry , polymer
Short, alpha‐helical coiled coils provide a simple, modular method to direct the assembly of proteins into higher order structures. We previously demonstrated that by genetically fusing de novo–designed coiled coils of the appropriate oligomerization state to a natural trimeric protein, we could direct the assembly of this protein into various geometrical cages. Here, we have extended this approach by appending a coiled coil designed to trimerize in response to binding divalent transition metal ions and thereby achieve metal ion‐dependent assembly of a tetrahedral protein cage. Ni 2+ , Co 2+ , Cu 2+ , and Zn 2+ ions were evaluated, with Ni 2+ proving the most effective at mediating protein assembly. Characterization of the assembled protein indicated that the metal ion–protein complex formed discrete globular structures of the diameter expected for a complex containing 12 copies of the protein monomer. Protein assembly could be reversed by removing metal ions with ethylenediaminetetraacetic acid or under mildly acidic conditions.