5AJI

MscS D67R1 high resolution

Summary for 5AJI

• Entry DOI: 10.2210/pdb5aji/pdb
• Related: 5AIT 5AIU
• Descriptor: SMALL-CONDUCTANCE MECHANOSENSITIVE CHANNEL, N-OCTANE, HEXANE, ... (4 entities in total)
• Functional Keywords: transport protein
• Biological source: ESCHERICHIA COLI
• Cellular location: Cell inner membrane ; Multi- pass membrane protein : P0C0S2
• Total number of polymer chains: 7
• Total formula weight: 219183.69

Authors

Naismith, J.H.,Pliotas, C. (deposition date: 2015-02-24, release date: 2015-07-08, Last modification date: 2024-01-10)

Primary citation

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.
The Role of Lipids in Mechanosensation.
Nat.Struct.Mol.Biol., 22:991-, 2015

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.

PubMed: 26551077
DOI: 10.1038/NSMB.3120

Experimental method

X-RAY DIFFRACTION (2.99 Å)