Publication Date:
2008-08-30
Description:
The mechanosensitive channel of small conductance (MscS) is a key determinant in the prokaryotic response to osmotic challenges. We determined the structural rearrangements associated with MscS activation in membranes, using functorial measurements, electron paramagnetic resonance spectroscopy, and computational analyses. MscS was trapped in its open conformation after the transbilayer pressure profile was modified through the asymmetric incorporation of lysophospholipids. The transition from the closed to the open state is accompanied by the downward tilting of the transmembrane TM1-TM2 hairpin and by the expansion, tilt, and rotation of the TM3 helices. These movements expand the permeation pathway, leading to an increase in accessibility to water around TM3. Our open MscS model is compatible with single-channel conductance measurements and supports the notion that helix tilting is associated with efficient pore widening in mechanosensitive channels.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2897165/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉 〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2897165/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Vasquez, Valeria -- Sotomayor, Marcos -- Cordero-Morales, Julio -- Schulten, Klaus -- Perozo, Eduardo -- 1 R01 GM067887/GM/NIGMS NIH HHS/ -- GM063617/GM/NIGMS NIH HHS/ -- P41 RR005969/RR/NCRR NIH HHS/ -- P41 RR005969-19/RR/NCRR NIH HHS/ -- P41-RR05969/RR/NCRR NIH HHS/ -- R01 GM067887/GM/NIGMS NIH HHS/ -- R01 GM067887-05/GM/NIGMS NIH HHS/ -- Howard Hughes Medical Institute/ -- New York, N.Y. -- Science. 2008 Aug 29;321(5893):1210-4. doi: 10.1126/science.1159674.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22908, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18755978" target="_blank"〉PubMed〈/a〉
Keywords:
Electron Spin Resonance Spectroscopy
;
Escherichia coli Proteins/*chemistry/genetics/*physiology
;
*Ion Channel Gating
;
Ion Channels/*chemistry/genetics/*physiology
;
*Lipid Bilayers
;
Lysophosphatidylcholines
;
Micelles
;
Models, Molecular
;
Mutant Proteins/chemistry/metabolism
;
Patch-Clamp Techniques
;
Pressure
;
Protein Conformation
;
Protein Structure, Secondary
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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