Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA.
Department of Molecular Biology, Princeton University, Princeton, NJ, USA.
Nat Commun. 2021 Jun 18;12(1):3744. doi: 10.1038/s41467-021-24124-6.
Bacteria use extracellular appendages called type IV pili (T4P) for diverse behaviors including DNA uptake, surface sensing, virulence, protein secretion, and twitching motility. Dynamic extension and retraction of T4P is essential for their function, and T4P extension is thought to occur through the action of a single, highly conserved motor, PilB. Here, we develop Acinetobacter baylyi as a model to study T4P by employing a recently developed pilus labeling method. By contrast to previous studies of other bacterial species, we find that T4P synthesis in A. baylyi is dependent not only on PilB but also on an additional, phylogenetically distinct motor, TfpB. Furthermore, we identify a protein (CpiA) that inhibits T4P extension by specifically binding and inhibiting PilB but not TfpB. These results expand our understanding of T4P regulation and highlight how inhibitors might be exploited to disrupt T4P synthesis.
细菌使用称为 IV 型菌毛（T4P）的细胞外附属物来实现多种行为，包括 DNA 摄取、表面感应、毒力、蛋白质分泌和蠕动运动。T4P 的动态延伸和缩回对于它们的功能至关重要，并且 T4P 的延伸被认为是通过单个高度保守的马达 PilB 的作用发生的。在这里，我们通过采用最近开发的菌毛标记方法，将鲍曼不动杆菌开发为研究 T4P 的模型。与先前对其他细菌物种的研究相比，我们发现 A. baylyi 中的 T4P 合成不仅依赖于 PilB，还依赖于另一种进化上不同的马达 TfpB。此外，我们鉴定出一种蛋白质（CpiA），它通过特异性结合和抑制 PilB 但不抑制 TfpB 来抑制 T4P 延伸。这些结果扩展了我们对 T4P 调节的理解，并强调了抑制剂如何被用来破坏 T4P 合成。
