9p0n

MscS in Glyco-DIBMA Native Nanodiscs (C7 symmetry)

spinqualitylabelsall models 9p0n, resolution 2.99Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 9p0n is a 7 chain structure with sequence from Escherichia coli. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: Electron Microscopy, Resolution 2.99Å Ligands: D21 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function 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). Publication Abstract from PubMed Interpretations of experimental conformations of mechanosensitive channels gated by 'force from lipids' become more reliable when native lipids are preserved in the structures. Escherichia coli MscS is an adaptive osmolyte release valve that regulates turgor in osmotically stressed cells. MscS promptly opens under abrupt super-threshold tensions in the membrane, but at lower and more gradually applied tensions, it silently inactivates from the closed state. A central question has been whether to assign the commonly observed non-conductive conformation with splayed peripheral helices to a closed or inactivated state. We present a 3-A MscS cryo-EM structure obtained in Glyco-DIBMA polymers, which avoid complete lipid removal. Within the complex, we observe densities for endogenous phospholipids intercalating between the peripheral and pore-lining helices. The lipidomic analysis shows a 2-3 fold enrichment of phosphatidylglycerol in Glyco-DIBMA-extracted MscS samples. The computed pressure of these lipids on the protein surface enforces the characteristic kinks in the pore-lining helices, sterically stabilizing the separation of the peripheral helices. Mutations of residues coordinating lipids in the crevices eliminate inactivation, allowing us to classify this group of structures as the inactivated state. Our study reveals a novel inactivation mechanism in which intercalated lipids physically decouple the tension-sensing helices from the gate. The lipid-mediated mechanism of mechanosensitive channel MscS inactivation.,Moller E, Britt M, Zhou F, Yang H, Anishkin A, Ernst R, Vanegas JM, Sukharev S, Matthies D bioRxiv [Preprint]. 2025 Sep 10:2024.01.22.576751. doi: , 10.1101/2024.01.22.576751. PMID:38328078 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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