1.A.23.4.11
Mitochondrial mechanosensitive ion channel protein 1, MscS-like channel, MSL1, of 497 aas and 5 TMSs. As the sole member of the Arabidopsis MSL family, localized in the mitochondrial inner membrane, MSL1 is essential for maintaining the normal membrane potential of mitochondria. Li et al. 2020 reported a cryoelectron microscopy (cryo-EM) structure of AtMSL1 at 3.3 Å. The overall architecture of AtMSL1 is similar to MscS, but the transmembrane domain of AtMSL1 is larger. Structural differences are observed in both the transmembrane and the matrix domain, and the carboxyl-terminus of AtMSL1 is more flexible while the beta-barrel structure observed in MscS is absent. The side portals in AtMSL1 are significantly smaller, and enlarging the size of the portal by mutagenesis can increase the channel conductance (Li et al. 2020).