The alpha-helix and the organization and gating of channels
- Creators
- Spencer, Robert H.
-
Rees, Douglas C.
Abstract
The structures of an increasing number of channels and other a-helical membrane proteins have been determined recently, including the KcsA potassium channel, the MscL mechanosensitive channel, and the AQP1 and GlpF members of the aquaporin family. In this chapter, the orientation and packing characteristics of bilayer-spanning helices are surveyed in integral membrane proteins. In the case of channels, a-helices create the scaled barrier that separates the hydrocarbon region of the bilayer from the permeation pathway for solutes. The helices surrounding the permeation pathway tend to be rather steeply tilted relative to the membrane normal and are consistently arranged in a right-handed bundle. The helical framework further provides a supporting scaffold for nonmembrane-spanning structures associated with channel selectivity. Although structural details remain scarce, the conformational changes associated with gating transitions between closed and open states of channels are reviewed, emphasizing the potential roles of helix-helix interactions in this process.
Additional Information
"Reprinted, with permission, from the Annual Review of Biophysics and Biomolecular Structure, Volume 31 copyright 2002 by Annual Reviews, www.annualreviews.org" Discussions with Randal Bass, Kaspar Locher, Pavel Strop, Allen Lee, Margaret Barclay, Dennis Dougherty, Henry Lester, and Chris Miller are greatly appreciated. This work was supported in part by NIH grant GM62532.Files
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Additional details
- Eprint ID
- 1567
- Resolver ID
- CaltechAUTHORS:SPEarbbs02
- Created
-
2006-01-30Created from EPrint's datestamp field
- Updated
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2021-11-08Created from EPrint's last_modified field