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Updated: Sep 27, 2026
From Constructs to Crystals – Towards Structure Determination of β-barrel Outer Membrane Proteins
Published on: July 4, 2016
Crystallization and initial X-ray diffraction of BtuB, the integral membrane cobalamin transporter of Escherichia
David P Chimento1, Arun K Mohanty, Robert J Kadner
1Department of Microbiology, University of Virginia, Charlottesville, Virginia 22908, USA.
Abstract:
BtuB, the cobalamin transporter from Escherichia coli, has been overexpressed, purified and crystallized. The purified protein was solubilized in n-octyl tetraoxyethylene (C(8)E(4)) and was crystallized using sitting-drop vapor diffusion with PEG 3350 and magnesium acetate as precipitants (pH 6.5). Two crystal forms have been obtained. Crystal type I belongs to space group P3(1)21, with unit-cell parameters a = b = 81.6, c = 210.0 A, alpha = beta = 90, gamma = 120 degrees. Crystal type II belongs to space group P3(1)21, with unit-cell parameters a = b = 81.6, c = 226.0 A, alpha = beta = 90, gamma = 120 degrees. Each crystal form contains a monomer in the asymmetric unit. Diffraction for crystal type I extends to 2.0 A and diffraction for crystal type II extends to 2.7 A. Both crystal forms are suitable for structure determination.
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