Download MendeleyStructure and selectivity in bestrophin ion channels.
Yang, T., Liu, Q., Kloss, B., Bruni, R., Kalathur, R.C., Guo, Y., Kloppmann, E., Rost, B., Colecraft, H.M., Hendrickson, W.A.(2014) Science 346: 355-359
- PubMed: 25324390
- DOI: https://doi.org/10.1126/science.1259723
- Primary Citation of Related Structures:
4WD7, 4WD8 - PubMed Abstract:
Human bestrophin-1 (hBest1) is a calcium-activated chloride channel from the retinal pigment epithelium, where mutations are associated with vitelliform macular degeneration, or Best disease. We describe the structure of a bacterial homolog (KpBest) of hBest1 and functional characterizations of both channels. KpBest is a pentamer that forms a five-helix transmembrane pore, closed by three rings of conserved hydrophobic residues, and has a cytoplasmic cavern with a restricted exit. From electrophysiological analysis of structure-inspired mutations in KpBest and hBest1, we find a sensitive control of ion selectivity in the bestrophins, including reversal of anion/cation selectivity, and dramatic activation by mutations at the cytoplasmic exit. A homology model of hBest1 shows the locations of disease-causing mutations and suggests possible roles in regulation.
Organizational Affiliation:
Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA.
