6CTD

C-terminal domain truncation of the Mycobacterium tuberculosis Mechanosensitive Channel of Large Conductance MscL

Summary for 6CTD

• Entry DOI: 10.2210/pdb6ctd/pdb
• Descriptor: Large-conductance mechanosensitive channel, GOLD ION (2 entities in total)
• Functional Keywords: channel mechanosensitive mycobacterium tuberculosis, membrane protein
• Biological source: Mycobacterium tuberculosis (strain ATCC 25177 / H37Ra)
• Total number of polymer chains: 10
• Total formula weight: 131908.14

Authors

Herrera, N.,Rees, D.C. (deposition date: 2018-03-22, release date: 2018-10-10, Last modification date: 2024-03-13)

Primary citation

Herrera, N.,Maksaev, G.,Haswell, E.S.,Rees, D.C.
Elucidating a role for the cytoplasmic domain in the Mycobacterium tuberculosis mechanosensitive channel of large conductance.
Sci Rep, 8:14566-14566, 2018

PubMed 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 influence 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 influences 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.

PubMed: 30275500
DOI: 10.1038/s41598-018-32536-6

Experimental method

X-RAY DIFFRACTION (5.8 Å)