title: Growth of large and highly ordered 2D crystals of a K⁺ channel, structural role of lipidic environment.
abstract: 2D crystallography has proven to be an excellent technique to determine the 3D structure of membrane proteins. Compared to 3D crystallography, it has the advantage of visualizing the protein in an environment closer to the native one. However, producing good 2D crystals is still a challenge and little statistical knowledge can be gained from literature. Here, we present a thorough screening of 2D crystallization conditions for a prokaryotic inwardly rectifying potassium channel (>130 different conditions). Key parameters leading to very large and well-organized 2D crystals are discussed. In addition, the problem of formation of multilayers during the growth of 2D crystals is also addressed. An intermediate resolution projection map of KirBac3.1 at 6 Å is presented, which sheds (to our knowledge) new light on the structure of this channel in a lipid environment.
authors.affiliation: Laboratory of Molecular Biophysics, Department of Biochemistry, University of Oxford, Oxford, United Kingdom.
authors.forename: Rita
authors.initials: R
authors.lastname: De Zorzi
authors.forename: William V
authors.initials: WV
authors.lastname: Nicholson
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Guigner
authors.forename: Françoise
authors.initials: F
authors.lastname: Erne-Brand
authors.forename: Catherine
authors.initials: C
authors.lastname: Vénien-Bryan
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry*; D003460:Crystallization; D008055:Lipids / Q000737:chemistry*; D009154:Mutation; D024661:Potassium Channels, Inwardly Rectifying / Q000737:chemistry* / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D008055:Lipids; D024661:Potassium Channels, Inwardly Rectifying