4AGF

MTSSL spin labeled L124C mutant of MscS in the open form

Summary for 4AGF

• Entry DOI: 10.2210/pdb4agf/pdb
• Related: 2VV5 4AGE
• Descriptor: SMALL-CONDUCTANCE MECHANOSENSITIVE CHANNEL (1 entity in total)
• Functional Keywords: membrane protein
• Biological source: ESCHERICHIA COLI
• Cellular location: Cell inner membrane; Multi-pass membrane protein (By similarity): P0C0S2
• Total number of polymer chains: 7
• Total formula weight: 216390.21

Authors

Pliotas, C.,Brannigan, E.,Naismith, J.H. (deposition date: 2012-01-26, release date: 2012-08-15, Last modification date: 2023-12-20)

Primary citation

Pliotas, C.,Ward, R.,Branigan, E.,Rasmussen, A.,Hagelueken, G.,Huang, H.,Black, S.S.,Booth, I.R.,Schiemann, O.,Naismith, J.H.
Conformational State of the Mscs Mechanosensitive Channel in Solution Revealed by Pulsed Electron-Electron Double Resonance (Peldor) Spectroscopy.
Proc.Natl.Acad.Sci.USA, 109:E2675-, 2012

PubMed Abstract: The heptameric mechanosensitive channel of small conductance (MscS) provides a critical function in Escherichia coli where it opens in response to increased bilayer tension. Three approaches have defined different closed and open structures of the channel, resulting in mutually incompatible models of gating. We have attached spin labels to cysteine mutants on key secondary structural elements specifically chosen to discriminate between the competing models. The resulting pulsed electron-electron double resonance (PELDOR) spectra matched predicted distance distributions for the open crystal structure of MscS. The fit for the predictions by structural models of MscS derived by other techniques was not convincing. The assignment of MscS as open in detergent by PELDOR was unexpected but is supported by two crystal structures of spin-labeled MscS. PELDOR is therefore shown to be a powerful experimental tool to interrogate the conformation of transmembrane regions of integral membrane proteins.

PubMed: 23012406
DOI: 10.1073/PNAS.1202286109

Experimental method

X-RAY DIFFRACTION (4.7 Å)