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| | ==The open structure of MscS== | | ==The open structure of MscS== |
| - | <StructureSection load='2vv5' size='340' side='right' caption='[[2vv5]], [[Resolution|resolution]] 3.45Å' scene=''> | + | <StructureSection load='2vv5' size='340' side='right'caption='[[2vv5]], [[Resolution|resolution]] 3.45Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[2vv5]] is a 7 chain structure with sequence from [http://en.wikipedia.org/wiki/"bacillus_coli"_migula_1895 "bacillus coli" migula 1895]. The November 2008 RCSB PDB [http://pdb.rcsb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/index.html Molecule of the Month] feature on ''Mechanosensitive Channels'' by David Goodsell is [http://dx.doi.org/10.2210/rcsb_pdb/mom_2008_11 10.2210/rcsb_pdb/mom_2008_11]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2VV5 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2VV5 FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[2vv5]] is a 7 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. The November 2008 RCSB PDB [https://pdb.rcsb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/index.html Molecule of the Month] feature on ''Mechanosensitive Channels'' by David Goodsell is [https://dx.doi.org/10.2210/rcsb_pdb/mom_2008_11 10.2210/rcsb_pdb/mom_2008_11]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2VV5 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2VV5 FirstGlance]. <br> |
| - | </td></tr><tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2vv5 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2vv5 OCA], [http://pdbe.org/2vv5 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=2vv5 RCSB], [http://www.ebi.ac.uk/pdbsum/2vv5 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=2vv5 ProSAT]</span></td></tr> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 3.45Å</td></tr> |
| | + | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=2vv5 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2vv5 OCA], [https://pdbe.org/2vv5 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2vv5 RCSB], [https://www.ebi.ac.uk/pdbsum/2vv5 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2vv5 ProSAT]</span></td></tr> |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/MSCS_ECO57 MSCS_ECO57]] Mechanosensitive channel that participates in the regulation of osmotic pressure changes within the cell. Forms an ion channel of 1.0 nanosiemens conductance with a slight preference for anions. The channel is sensitive to voltage (By similarity). | + | [https://www.uniprot.org/uniprot/MSCS_ECOLI MSCS_ECOLI] Mechanosensitive channel that participates in the regulation of osmotic pressure changes within the cell, opening in response to stretch forces in the membrane lipid bilayer, without the need for other proteins. Forms an ion channel of 1.0 nanosiemens conductance with a slight preference for anions. The channel is sensitive to voltage; as the membrane is depolarized, less tension is required to open the channel and vice versa. The channel is characterized by short bursts of activity that last for a few seconds. The channel pore is formed by TM3 and the loop between TM2 and TM3. After a sharp turn at Gly-113, an alpha-helix (residues 114-127) is oriented nearly parallel to the plane of the putative lipid bilayer. On the intracellular side of the channel, the permeation pathway of MscS does not connect directly to the cytoplasm but instead opens to a large chamber that is connected to the cytoplasm. This chamber resembles a molecular filter that could serve to prescreen large molecules before they are allowed passage to the transmembrane pore. The TM1 and TM2 helices appear to be likely candidates for mediating the tension and voltage sensitivities of MscS. Gating requires large rearrangements of at least the C-terminus. |
| | == Evolutionary Conservation == | | == Evolutionary Conservation == |
| | [[Image:Consurf_key_small.gif|200px|right]] | | [[Image:Consurf_key_small.gif|200px|right]] |
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| | ==See Also== | | ==See Also== |
| - | *[[Ion channels|Ion channels]] | + | *[[Ion channels 3D structures|Ion channels 3D structures]] |
| - | *[[Mechanosensitive channels: opening and closing|Mechanosensitive channels: opening and closing]]
| + | |
| | == References == | | == References == |
| | <references/> | | <references/> |
| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Bacillus coli migula 1895]] | + | [[Category: Escherichia coli]] |
| | + | [[Category: Large Structures]] |
| | [[Category: Mechanosensitive Channels]] | | [[Category: Mechanosensitive Channels]] |
| | [[Category: RCSB PDB Molecule of the Month]] | | [[Category: RCSB PDB Molecule of the Month]] |
| - | [[Category: Dong, C]] | + | [[Category: Dong C]] |
| - | [[Category: Johnson, K A]] | + | [[Category: Johnson KA]] |
| - | [[Category: Naismith, J H]] | + | [[Category: Naismith JH]] |
| - | [[Category: Wang, W]] | + | [[Category: Wang W]] |
| - | [[Category: Inner membrane]]
| + | |
| - | [[Category: Ion transport]]
| + | |
| - | [[Category: Ionic channel]]
| + | |
| - | [[Category: Membrane]]
| + | |
| - | [[Category: Membrane protein]]
| + | |
| - | [[Category: Membrane structure]]
| + | |
| - | [[Category: Open channel]]
| + | |
| - | [[Category: Transmembrane]]
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| - | [[Category: Transport]]
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| Structural highlights
Function
MSCS_ECOLI Mechanosensitive channel that participates in the regulation of osmotic pressure changes within the cell, opening in response to stretch forces in the membrane lipid bilayer, without the need for other proteins. Forms an ion channel of 1.0 nanosiemens conductance with a slight preference for anions. The channel is sensitive to voltage; as the membrane is depolarized, less tension is required to open the channel and vice versa. The channel is characterized by short bursts of activity that last for a few seconds. The channel pore is formed by TM3 and the loop between TM2 and TM3. After a sharp turn at Gly-113, an alpha-helix (residues 114-127) is oriented nearly parallel to the plane of the putative lipid bilayer. On the intracellular side of the channel, the permeation pathway of MscS does not connect directly to the cytoplasm but instead opens to a large chamber that is connected to the cytoplasm. This chamber resembles a molecular filter that could serve to prescreen large molecules before they are allowed passage to the transmembrane pore. The TM1 and TM2 helices appear to be likely candidates for mediating the tension and voltage sensitivities of MscS. Gating requires large rearrangements of at least the C-terminus.
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
How ion channels are gated to regulate ion flux in and out of cells is the subject of intense interest. The Escherichia coli mechanosensitive channel, MscS, opens to allow rapid ion efflux, relieving the turgor pressure that would otherwise destroy the cell. We present a 3.45 angstrom-resolution structure for the MscS channel in an open conformation. This structure has a pore diameter of approximately 13 angstroms created by substantial rotational rearrangement of the three transmembrane helices. The structure suggests a molecular mechanism that underlies MscS gating and its decay of conductivity during prolonged activation. Support for this mechanism is provided by single-channel analysis of mutants with altered gating characteristics.
The structure of an open form of an E. coli mechanosensitive channel at 3.45 A resolution.,Wang W, Black SS, Edwards MD, Miller S, Morrison EL, Bartlett W, Dong C, Naismith JH, Booth IR Science. 2008 Aug 29;321(5893):1179-83. PMID:18755969[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Wang W, Black SS, Edwards MD, Miller S, Morrison EL, Bartlett W, Dong C, Naismith JH, Booth IR. The structure of an open form of an E. coli mechanosensitive channel at 3.45 A resolution. Science. 2008 Aug 29;321(5893):1179-83. PMID:18755969 doi:http://dx.doi.org/321/5893/1179
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