Premium
Structural modeling of dual‐affinity purified Pho84 phosphate transporter
Author(s) -
Lagerstedt Jens O.,
Voss John C.,
Wieslander Åke,
Persson Bengt L.
Publication year - 2004
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2004.11.012
Subject(s) - transporter , antiporter , antiporters , transmembrane protein , site directed spin labeling , chemistry , biochemistry , biophysics , crystallography , biology , membrane , gene , receptor
The phosphate transporter Pho84 of Saccharomyces cerevisiae is predicted to contain 12 transmembrane (TM) regions, divided into two partially duplicated parts of 6 TM segments. The three‐dimensional (3D) organization of the Pho84 protein has not yet been determined. However, the 3D crystal structure of the Escherichia coli MFS glycerol‐3‐phosphate/phosphate antiporter, GlpT, and lactose transporter, LacY, has recently been determined. On the basis of extensive prediction and fold recognition analyses (at the MetaServer), GlpT was proposed as the best structural template on which the arrangement of TM segments of the Pho84 transporter was fit, using the comparative structural modeling program MODELLER. To initiate an evaluation of the appropriateness of the Pho84 model, we have performed two direct tests by targeting spin labels to putative TM segments 8 and 12. Electron paramagnetic resonance spectroscopy was then applied on purified and spin labeled Pho84. The line shape from labels located at both positions is consistent with the structural environment predicted by the template‐generated model, thus supporting the model.