Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA.
Protein Sci. 2010 Apr;19(4):808-14. doi: 10.1002/pro.360.
Several archaeal mechanosensitive (MS) channels have been reported, including one from Thermoplasma volcanium designated MscTV. Here, we report the crystal structure of MscTV at 1.6-A resolution. Unexpectedly, MscTV was found to be a water-soluble protein exhibiting a winged helix-turn-helix (wHTH) motif, which is the signature of the MarR (multiple antibiotic resistance regulator) family of transcriptional regulators. A cell-based osmotic downshock functional assay demonstrated that MscTV was unable to protect a knockout strain of Escherichia coli from hypoosmotic shock, further indicating that it does not function as a MS channel. We propose this protein be renamed MLPTv for MarR-like protein from T. volcanium.
已经报道了几种古菌机械敏感（MS）通道，包括一种来自 Thermoplasma volcanium 的 MscTV。在这里，我们报道了 MscTV 的晶体结构，分辨率为 1.6-A。出乎意料的是，MscTV 被发现是一种水溶性蛋白质，具有翼状螺旋-转角-螺旋（wHTH）基序，这是 MarR（多种抗生素耐药调节剂）家族转录调节剂的特征。基于细胞的渗透休克功能测定表明，MscTV 不能保护大肠杆菌的敲除菌株免受低渗休克，这进一步表明它不能作为 MS 通道发挥作用。我们建议将这种蛋白质重新命名为 MLPTv，代表来自 Thermoplasma volcanium 的 MarR 样蛋白。
