Two-dimensional crystals of carboxysome shell proteins recapitulate the hexagonal packing of three-dimensional crystals.
Bacterial microcompartments (BMCs) are large intracellular bodies that serve as simple organelles in many bacteria. They are proteinaceous structures composed of key enzymes encapsulated by a polyhedral protein shell. In previous studies, the organization of these large shells has been inferred from the conserved packing of the component shell proteins in two-dimensional (2D) layers within the context of three-dimensional (3D) crystals. Here, we show that well-ordered, 2D crystals of carboxysome shell proteins assemble spontaneously when His-tagged proteins bind to a monolayer of nickelated lipid molecules at an air-water interface. The molecular packing within the 2D crystals recapitulates the layered hexagonal sheets observed in 3D crystals. The results reinforce current models for the molecular design of BMC shells.
Department of Molecular Physiology and Biological Physics, University of Virginia Health System, Charlottesville, Virginia 22908, USA.
Kelly A
KA
Dryden
Christopher S
CS
Crowley
Shiho
S
Tanaka
Todd O
TO
Yeates
Mark
M
Yeager
D001426:Bacterial Proteins / Q000737:chemistry*; D003460:Crystallization / Q000379:methods*; D008055:Lipids / Q000737:chemistry; D008854:Microscopy, Electron; D009532:Nickel / Q000737:chemistry; D046939:Synechocystis / Q000737:chemistry*
D001426:Bacterial Proteins; D008055:Lipids; D009532:Nickel