Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany; email:
Annu Rev Microbiol. 2019 Sep 8;73:247-265. doi: 10.1146/annurev-micro-102215-095531. Epub 2019 May 29.
Tc toxin complexes are virulence factors of many bacteria, including insect and human pathogens. Tc toxins are composed of three subunits that act together to perforate the host membrane, similar to a syringe, and translocate toxic enzymes into the host cell. The reactions of the toxic enzymes lead to deterioration and ultimately death of the cell. We review recent high-resolution structural and functional data that explain the mechanism of action of this type of bacterial toxin at an unprecedented level of molecular detail. We focus on the steps that are necessary for toxin activation and membrane permeation. This is where the largest conformational transitions appear. Furthermore, we compare the architecture and function of Tc toxins with those of anthrax toxin and vertebrate teneurin.
Tc 毒素复合物是许多细菌的毒力因子，包括昆虫和人类病原体。Tc 毒素由三个亚基组成，它们协同作用刺穿宿主膜，类似于注射器，并将毒性酶转移到宿主细胞中。毒性酶的反应导致细胞恶化并最终死亡。我们回顾了最近的高分辨率结构和功能数据，这些数据以前所未有的分子细节水平解释了这种类型的细菌毒素的作用机制。我们专注于毒素激活和膜渗透所必需的步骤。这是出现最大构象转变的地方。此外，我们还比较了 Tc 毒素与炭疽毒素和脊椎动物 tenurin 的结构和功能。
