4hw9

Publication Abstract from PubMed

The mechanosensitive channel of small conductance (MscS) contributes to the survival of bacteria during osmotic downshock by transiently opening large diameter pores for the efflux of cellular contents before the membrane ruptures. Two crystal structures of the Escherichia coliMscS are currently available, the wild type protein in a non-conducting state at 3.7 A resolution(Bass et al., Science 298, 1582 (2002)) and the Ala106Val variant in an open state at 3.45 A resolution (Wang et al., Science 321, 1179 (2008)). Both structures used protein solubilized in the detergent fos-choline-14. We report here crystal structures of MscS from Escherichia coli and Helicobacter pylori solubilized in the detergent beta-dodecylmaltoside (DDM) at resolutions of 4.4 and 4.2 A, respectively. While the cytoplasmic domains are unchanged in these structures, distinctconformations of the transmembrane domains are observed. Intriguingly, DDM solubilized wild type E. coliMscSadopts the open state structure of A106V E. coliMscS, while H. pyloriMscS resembles the non-conducting state structure observed for fos-choline-14 solubilized E. coliMscS. These results highlight the sensitivity of membrane protein conformational equilibria to variationsin detergent, crystallization conditions and protein sequence.

Open and shut: Crystal structures of the dodecylmaltoside solubilized mechanosensitive channel of small conductance from E. coli and H. pylori at 4.4 A and 4.1 A resolution.,Lai JY, Poon YS, Kaiser JT, Rees DC Protein Sci. 2013 Jan 22. doi: 10.1002/pro.2222. PMID:23339071^[1]

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