Crystallization and preliminary crystallographic analysis of the Escherichia coli water channel AqpZ

• Published in: Acta crystallographica. Section D, Biological crystallography. Biological crystallography., 2004-03, Vol.60 (3), p.561-563
• Main Authors: Daniels, Brenda V., Jiang, Jian-Sheng, Fu, Dax
• Format: Article
• Language: English
• Subjects: AqpZ; Aquaporins - chemistry; Aquaporins - genetics; Aquaporins - metabolism; Crystallization; Crystallography, X-Ray; Detergents - chemistry; Escherichia coli - enzymology; Escherichia coli - genetics; Escherichia coli Proteins - chemistry; Escherichia coli Proteins - genetics; Escherichia coli Proteins - metabolism; Membrane Proteins - chemistry; Membrane Proteins - genetics; Membrane Proteins - metabolism; Recombinant Fusion Proteins - chemistry; Recombinant Fusion Proteins - genetics; Recombinant Fusion Proteins - metabolism; Water - metabolism; water channels
• ISSN: 1399-0047; 0907-4449; 1399-0047
• DOI: 10.1107/S090744490302972X

AqpZ is a 24 kDa integral membrane protein that facilitates water movement across the plasma membrane of Escherichia coli. In this study, the first crystallization and preliminary X‐ray analysis of AqpZ are described. AqpZ was overexpressed and purified with a yield of 13 mg of purified AqpZ per litre of cell culture. The purified AqpZ was shown to be a monodisperse species consisting of tetrameric protein–detergent complexes. A crystallization condition for producing diffraction‐quality crystals was identified. Initial X‐ray analysis indicated that the diffraction limit of AqpZ extended to 3.6 Å. Crystals were found to belong to space groups P4122 or P4322, with unit‐cell parameters a = b = 119.04, c = 380.23 Å.