Biological Assembly 1  

 3D View: Structure | Electron Density | Ligand Interaction

Global Symmetry: Cyclic - C7  (3D View)
Global Stoichiometry: Homo 7-mer - A7 

Biological assembly 1 assigned by authors and generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 219.18 kDa 
• Atom Count: 13963 
• Modelled Residue Count: 1809 
• Deposited Residue Count: 2002 
• Unique protein chains: 1

5AJI

MscS D67R1 high resolution

• DOI: 10.2210/pdb5AJI/pdb

• Classification: TRANSPORT PROTEIN
• Organism(s): Escherichia coli
• Expression System: Escherichia coli
• Mutation(s): Yes 


• Deposited: 2015-02-24 Released: 2015-07-08 
• Deposition Author(s): Naismith, J.H., Pliotas, C.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.99 Å
• R-Value Free: 0.263 
• R-Value Work: 0.244 
• R-Value Observed: 0.245 

Literature

The Role of Lipids in Mechanosensation.

Pliotas, C., Dahl, A.C.E., Rasmussen, T., Mahendran, K.R., Smith, T.K., Marius, P., Gault, J., Banda, T., Rasmussen, A., Miller, S., Robinson, C.V., Bayley, H., Sansom, M.S.P., Booth, I.R., Naismith, J.H.

(2015) Nat Struct Mol Biol 22: 991

• PubMed: 26551077 
• DOI: 10.1038/nsmb.3120
• Primary Citation of Related Structures:  
  5AJI


• PubMed Abstract: 
  

The ability of proteins to sense membrane tension is pervasive in biology. A higher-resolution structure of the Escherichia coli small-conductance mechanosensitive channel MscS identifies alkyl chains inside pockets formed by the transmembrane helices (TMs). Purified MscS contains E. coli lipids, and fluorescence quenching demonstrates that phospholipid acyl chains exchange between bilayer and TM pockets. Molecular dynamics and biophysical analyses show that the volume of the pockets and thus the number of lipid acyl chains within them decreases upon channel opening. Phospholipids with one acyl chain per head group (lysolipids) displace normal phospholipids (with two acyl chains) from MscS pockets and trigger channel opening. We propose that the extent of acyl-chain interdigitation in these pockets determines the conformation of MscS. When interdigitation is perturbed by increased membrane tension or by lysolipids, the closed state becomes unstable, and the channel gates.

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Organizational Affiliation: 

State Key Laboratory of Biotherapy, Sichuan University, Chengdu, China.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
SMALL-CONDUCTANCE MECHANOSENSITIVE CHANNEL	A, B, C, D, E, F, G	286	Escherichia coli	Mutation(s): 1
Membrane protein Mpstruc	Group:  TRANSMEMBRANE PROTEINS: ALPHA-HELICAL		Sub Group:  Channels: Mechanosensitive	Protein:  MscS voltage-modulated mechanosensitive channel, D67R1 mutant
Find proteins for P0C0S1 (Escherichia coli (strain K12)) Explore P0C0S1  Go to UniProtKB:  P0C0S1

Small Molecules

Ligands 3 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
D10	L [auth C], O [auth D], V [auth G]	DECANE C10 H22 DIOQZVSQGTUSAI-UHFFFAOYSA-N
OCT	H [auth A], Q [auth E]	N-OCTANE C8 H18 TVMXDCGIABBOFY-UHFFFAOYSA-N
HEX	I [auth A],  J [auth B],  K [auth B],  M [auth C],  N [auth C],  P [auth D],  R [auth E],  S [auth E],  T [auth F],  U [auth F]	HEXANE C6 H14 VLKZOEOYAKHREP-UHFFFAOYSA-N

Modified Residues  1 Unique
ID	Chains	Type	Formula	2D Diagram	Parent
R1A	A, B, C, D, E, F, G	L-PEPTIDE LINKING	C12 H21 N2 O3 S2		CYS

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.99 Å
• R-Value Free: 0.263 
• R-Value Work: 0.244 
• R-Value Observed: 0.245 
• Space Group: P 2₁ 2₁ 2₁

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 126.33	α = 90
b = 149.09	β = 90
c = 173.82	γ = 90

Software Package:

Software Name	Purpose
REFMAC	refinement

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2015-02-24 
• Released Date: 2015-07-08 
Deposition Author(s): Naismith, J.H., Pliotas, C.

Revision History  

• Version 1.0: 2015-07-08
  Type: Initial release
  
• Version 1.1: 2015-11-18
  Changes: Database references
• Version 1.2: 2015-12-23
  Changes: Database references