Abstract
The mechanism by which potassium ions are transported through ion channels is currently being investigated by several groups using many different techniques. Clarification of the location of water molecules during transport is central to understanding how these integral membrane proteins function. Neutrons have a unique sensitivity to both hydrogen and potassium, rendering neutron crystallography capable of distinguishing waters from K+ ions. Here, the collection of a complete neutron data set from a potassium ion channel to a resolution of 3.55 Å using the Macromolecular Neutron Diffractometer (MaNDi) is reported. A room-temperature X-ray data set was also collected from the same crystal to a resolution of 2.50 Å. Upon further refinement, these results will help to further clarify the ion/water population within the selectivity filter of potassium ion channels.The growth of a large crystal of a potassium ion channel, and neutron and X-ray data collection from the crystal are described.
Original language | English |
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Pages (from-to) | 435-438 |
Number of pages | 4 |
Journal | Acta Crystallographica Section F:Structural Biology Communications |
Volume | 75 |
Issue number | 6 |
DOIs | |
State | Published - Jun 2019 |
Funding
Research at ORNL’s Spallation Neutron Source was sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, US Department of Energy. The Office of Biological and Environmental Research supported research at Oak Ridge National Laboratory’s Center for Structural Molecular Biology (CSMB) using facilities supported by the Scientific User Facilities Division, Office of Basic Energy Sciences, US Department of Energy. LC thanks Youxing Jiang and Nam Nguyen from UT Southwestern for kind help and advice on the expression and crystallization of the protein. Use of the Biomolecular Crystallography Facility in the Vanderbilt University Center for Structural Biology was supported through funds from Vanderbilt University Trans-Institutional Programs. BS is supported by NIH grant No. R01-GM071939.
Keywords
- X-ray diffraction
- ion channels
- membrane proteins
- neutron diffraction