View source for 4hwa


==Crystal Structure of Escherichia coli MscS Wildtype (Open State)==
<StructureSection load='4hwa' size='340' side='right'caption='[[4hwa]], [[Resolution|resolution]] 4.37&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4hwa]] is a 7 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli_K-12 Escherichia coli K-12]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4HWA OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4HWA FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 4.37&#8491;</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=4hwa FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4hwa OCA], [https://pdbe.org/4hwa PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4hwa RCSB], [https://www.ebi.ac.uk/pdbsum/4hwa PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4hwa ProSAT]</span></td></tr>
</table>
== Function ==
[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.

==See Also==
*[[Ion channels 3D structures|Ion channels 3D structures]]
__TOC__
</StructureSection>
[[Category: Escherichia coli K-12]]
[[Category: Large Structures]]
[[Category: Kaiser J]]
[[Category: Lai JY]]
[[Category: Poon YS]]
[[Category: Rees DC]]