Louvain Institute of Biomolecular Science and Technology, UCLouvain, Croix du Sud, 4-5, bte, L7.07.07., B-1348 Louvain-la-Neuve, Belgium.
Nano Lett. 2021 Apr 14;21(7):3075-3082. doi: 10.1021/acs.nanolett.1c00215. Epub 2021 Mar 23.
Bacterial pili are proteinaceous motorized nanomachines that play various functional roles including surface adherence, bacterial motion, and virulence. The surface-contact sensor type IVc (or Tad) pilus is widely distributed in both Gram-positive and Gram-negative bacteria. In , this nanofilament, though crucial for surface colonization, has never been thoroughly investigated at the molecular level. As assembles several surface appendages at specific stages of the cell cycle, we designed a fluorescence-based screen to selectively study single piliated cells and combined it with atomic force microscopy and genetic manipulation to quantify the nanoscale adhesion of the type IVc pilus to hydrophobic substrates. We demonstrate that this nanofilament exhibits high stickiness compared to the canonical type IVa/b pili, resulting mostly from multiple hydrophobic interactions along the fiber length, and that it features nanospring mechanical properties. Our findings may be helpful to better understand the structure-function relationship of bacterial pilus nanomachines.
细菌菌毛是蛋白驱动的纳米机器，在表面黏附、细菌运动和毒力等方面发挥着各种功能。表面接触传感器 IVc 型（或 Tad）菌毛广泛分布于革兰氏阳性菌和革兰氏阴性菌中。在 中，尽管这种纳米丝对于表面定殖至关重要，但它从未在分子水平上得到彻底研究。由于 在细胞周期的特定阶段组装几个表面附属物，我们设计了一种基于荧光的筛选方法来选择性地研究单个菌毛细胞，并将其与原子力显微镜和遗传操作相结合，以定量测量 IVc 型菌毛与疏水基底的纳米级黏附。我们证明，与典型的 IVa/b 菌毛相比，这种纳米丝表现出更高的粘性，这主要是由于纤维长度上的多个疏水相互作用，并且它具有纳米弹簧机械性能。我们的发现可能有助于更好地理解细菌菌毛纳米机器的结构-功能关系。
