Author's School

Arts & Sciences

Author's Department

Biology

Document Type

Article

Publication Date

10-1-2018

Originally Published In

Sci Rep. (2018) 8:14566. doi:10.1038/s41598-018-32536-6

Abstract

Microbial survival in dynamic environments requires the ability to successfully respond to abrupt changes in osmolarity. The mechanosensitive channel of large conductance (MscL) is a ubiquitous channel that facilitates the survival of bacteria and archaea under severe osmotic downshock conditions by relieving excess turgor pressure in response to increased membrane tension. A prominent structural feature of MscL, the cytoplasmic C-terminal domain, has been suggested to infuence channel assembly and function. In this report, we describe the X-ray crystal structure and electrophysiological properties of a C-terminal domain truncation of the Mycobacterium tuberculosis MscL (MtMscLΔC). A crystal structure of MtMscLΔC solubilized in the detergent n-dodecyl-β-D-maltopyranoside reveals the pentameric, closed state-like architecture for the membrane spanning region observed in the previously solved full-length MtMscL. Electrophysiological characterization demonstrates that MtMscLΔC retains mechanosensitivity, but with conductance and tension sensitivity more closely resembling full length EcMscL than MtMscL. This study establishes that the C-terminal domain of MtMscL is not required for oligomerization of the full-length channel, but rather infuences the tension sensitivity and conductance properties of the channel. The collective picture that emerges from these data is that each MscL channel structure has characteristic features, highlighting the importance of studying multiple homologs.

Comments

Originally published in Scientific Reports 8, Article number: 14566 (2018) doi:10.1038/s41598-018-32536-6

© The Author(s) 2018. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

Supplementary information accompanies this paper at https://doi.org/10.1038/s41598-018-32536-6.

DOI

doi:10.1038/s41598-018-32536-6

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