6pwp

From Proteopedia

(Difference between revisions)

Revision as of 04:41, 11 April 2020

MscS Nanodisc

6pwp, resolution 4.10Å

Structural highlights

6pwp is a 7 chain structure. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Experimental data:	Check to display Experimental Data
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

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.

Publication Abstract from PubMed

Prokaryotic mechanosensitive (MS) channels open by sensing the physical state of the membrane. As such, lipid-protein interactions represent the defining molecular process underlying mechanotransduction. Here, we describe cryo-electron microscopy (cryo-EM) structures of the E. coli small-conductance mechanosensitive channel (MscS) in nanodiscs (ND). They reveal a novel membrane-anchoring fold that plays a significant role in channel activation and establish a new location for the lipid bilayer, shifted ~14 A from previous consensus placements. Two types of lipid densities are explicitly observed. A phospholipid that 'hooks' the top of each TM2-TM3 hairpin and likely plays a role in force sensing, and a bundle of acyl chains occluding the permeation path above the L105 cuff. These observations reshape our understanding of force-from-lipids gating in MscS and highlight the key role of allosteric interactions between TM segments and phospholipids bound to key dynamic components of the channel.

Molecular basis of force-from-lipids gating in the mechanosensitive channel MscS.,Reddy B, Bavi N, Lu A, Park Y, Perozo E Elife. 2019 Dec 27;8. pii: 50486. doi: 10.7554/eLife.50486. PMID:31880537^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Reddy B, Bavi N, Lu A, Park Y, Perozo E. Molecular basis of force-from-lipids gating in the mechanosensitive channel MscS. Elife. 2019 Dec 27;8. pii: 50486. doi: 10.7554/eLife.50486. PMID:31880537 doi:http://dx.doi.org/10.7554/eLife.50486

1 Structural highlights
2 Function
3 Publication Abstract from PubMed
4 References

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/6pwp"

@@ Line 3: / Line 3: @@
 <SX load='6pwp' size='340' side='right' viewer='molstar' caption='[[6pwp]], [[Resolution|resolution]] 4.10&Aring;' scene=''>
 == Structural highlights ==
-<table><tr><td colspan='2'>[[6pwp]] is a 7 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6PWP OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6PWP FirstGlance]. <br>
+<table><tr><td colspan='2'>[[6pwp]] is a 7 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6PWP OCA]. For a <b>guided tour on the structure components</b> use [http://proteopedia.org/fgij/fg.htm?mol=6PWP 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=6pwp FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6pwp OCA], [http://pdbe.org/6pwp PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=6pwp RCSB], [http://www.ebi.ac.uk/pdbsum/6pwp PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=6pwp ProSAT]</span></td></tr>
+</td></tr><tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://proteopedia.org/fgij/fg.htm?mol=6pwp FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6pwp OCA], [http://pdbe.org/6pwp PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=6pwp RCSB], [http://www.ebi.ac.uk/pdbsum/6pwp PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=6pwp ProSAT]</span></td></tr>
 </table>
 == Function ==

6pwp

From Proteopedia

Revision as of 04:41, 11 April 2020

MscS Nanodisc

Structural highlights

Function

Publication Abstract from PubMed

References

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