title: Purification and crystallization of the cystic fibrosis transmembrane conductance regulator (CFTR).
abstract: The cystic fibrosis transmembrane conductance regulator (CFTR) is a membrane protein that is mutated in patients suffering from cystic fibrosis. Here we report the purification and first crystallization of wild-type human CFTR. Functional characterization of the material showed it to be highly active. Electron crystallography of negatively stained two-dimensional crystals of CFTR has revealed the overall architecture of this channel for two different conformational states. These show a strong structural homology to two conformational states of another eukaryotic ATP-binding cassette transporter, P-glycoprotein. In contrast to P-glycoprotein, however, both conformational states can be observed in the presence of a nucleotide, which may be related to the role of CFTR as an ion channel rather than a transporter. The hypothesis that the two conformations could represent the "open" and "closed" states of the channel is considered.
authors.affiliation: Department of Biomolecular Sciences, University of Manchester Institute of Science and Technology, Manchester M60 1QD, United Kingdom.
authors.forename: Mark F
authors.initials: MF
authors.lastname: Rosenberg
authors.forename: Alhaji Bukar
authors.initials: AB
authors.lastname: Kamis
authors.forename: Luba A
authors.initials: LA
authors.lastname: Aleksandrov
authors.forename: Robert C
authors.initials: RC
authors.lastname: Ford
authors.forename: John R
authors.initials: JR
authors.lastname: Riordan
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000737:chemistry; D018528:ATP-Binding Cassette Transporters / Q000737:chemistry; D000255:Adenosine Triphosphate / Q000737:chemistry; D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry; D006224:Cricetinae; D018360:Crystallography, X-Ray; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000737:chemistry* / Q000302:isolation & purification*; D019281:Dimerization; D004305:Dose-Response Relationship, Drug; D006801:Humans; D006868:Hydrolysis; D007668:Kidney / Q000378:metabolism; D008854:Microscopy, Electron; D009711:Nucleotides / Q000737:chemistry; D011487:Protein Conformation
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D018528:ATP-Binding Cassette Transporters; D001426:Bacterial Proteins; C505032:CFTR protein, human; C079726:MsbA protein, Bacteria; D009711:Nucleotides; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D000255:Adenosine Triphosphate