Two-Dimensional Crystalline Array Formation of Glucuronide Transporter from Escherichia coli by the Use of Polystyrene Beads for Detergent Removal

n -Dodecyl-β- d -maltoside solubilized glucuronide transporter (GusB), the product of gusB gene from Escherichia coli , was treated with Bio-Beads as an agent for removing the detergent from a micellar solution under suitable combination with dimyristoylphosphatidylcholine. Optimizing conditions led to a two-dimensional crystalline array formation of GusB. The crystalline arrays appear to have a hexagonal lattice with layer group P 6, the unit cell dimensions of a = b = 13.8 nm and γ = 120°. Each stain-protruding periodic unit showed approximately 11.8 ± 0.3 nm in a diameter in the inverse Fourier-filtered image to have formed with pentameric GusB (5 × 49.7 kDa).