On the structure of the N-terminal domain of the MscL channel: helical bundle or membrane interface.

ABSTRACT: The mechanosensitive channel of large conductance, MscL, serves as a biological emergency release valve protecting bacteria from acute osmotic downshock and is to date the best characterized mechanosensitive channel. A well-recognized and supported model for Escherichia coli MscL gating proposes that the N-terminal 11 amino acids of this protein form a bundle of amphipathic helices in the closed state that functionally serves as a cytoplasmic second gate. However, a recently reexamined crystal structure of a closed state of the Mycobacterium tuberculosis MscL shows these helices running along the cytoplasmic surface of the membrane. Thus, it is unclear if one structural model is correct or if they both reflect valid closed states. Here, we have systematically reevaluated this region utiliz

SUBMITTER: Iscla I 

PROVIDER: S-EPMC2517020 | biostudies-literature | 2008 Sep

REPOSITORIES: biostudies-literature