title: Self-assembly of "S-bilayers", a step toward expanding the dimensionality of S-layer assemblies.
abstract: Protein-based assemblies with ordered nanometer-scale features in three dimensions are of interest as functional nanomaterials but are difficult to generate. Here we report that a truncated S-layer protein assembles into stable bilayers, which we characterized using cryogenic-electron microscopy, tomography, and X-ray spectroscopy. We find that emergence of this supermolecular architecture is the outcome of hierarchical processes; the proteins condense in solution to form 2-D crystals, which then stack parallel to one another to create isotropic bilayered assemblies. Within this bilayered structure, registry between lattices in two layers was disclosed, whereas the intrinsic symmetry in each layer was altered. Comparison of these data to images of wild-type SbpA layers on intact cells gave insight into the interactions responsible for bilayer formation. These results establish a platform for engineering S-layer assemblies with 3-D architecture.
authors.affiliation: Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: Seong-Ho
authors.initials: SH
authors.lastname: Shin
authors.forename: Luis R
authors.initials: LR
authors.lastname: Comolli
authors.forename: Rupert
authors.initials: R
authors.lastname: Tscheliessnig
authors.forename: Cheng
authors.initials: C
authors.lastname: Wang
authors.forename: Ki Tae
authors.initials: KT
authors.lastname: Nam
authors.forename: Alexander
authors.initials: A
authors.lastname: Hexemer
authors.forename: Cristina E
authors.initials: CE
authors.lastname: Siegerist
authors.forename: James J
authors.initials: JJ
authors.lastname: De Yoreo
authors.forename: Carolyn R
authors.initials: CR
authors.lastname: Bertozzi
mesh_terms: D001406:Bacillaceae; D001426:Bacterial Proteins / Q000737:chemistry*; D008958:Models, Molecular; D036103:Nanotechnology / Q000379:methods*; D011487:Protein Conformation
chemical_list: D001426:Bacterial Proteins