Properties of the Mechanosensitive Channel MscS Pore Revealed by Tryptophan Scanning Mutagenesis.

ABSTRACT: Bacterial mechanosensitive channels gate when the transmembrane turgor rises to levels that compromise the structural integrity of the cell wall. Gating creates a transient large diameter pore that allows hydrated solutes to pass from the cytoplasm at rates close to those of diffusion. In the closed conformation, the channel limits transmembrane solute movement, even that of protons. In the MscS crystal structure (Protein Data Bank entry 2oau ), a narrow, hydrophobic opening is visible in the crystal structure, and it has been proposed that a vapor lock created by the hydrophobic seals, L105 and L109, is the barrier to water and ions. Tryptophan scanning mutagenesis has proven to be a highly valuable tool for the analysis of channel structure. Here Trp residues were introduced along the po

SUBMITTER: Rasmussen T 

PROVIDER: S-EPMC4519979 | biostudies-literature | 2015 Jul

REPOSITORIES: biostudies-literature