Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee, UK.
National Biofilms Innovation Centre, School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK.
Mol Microbiol. 2024 Oct;122(4):598-609. doi: 10.1111/mmi.15315. Epub 2024 Sep 30.
The extracellular matrix of biofilms provides crucial structural support to the community and protection from environmental perturbations. TasA, a key Bacillus subtilis biofilm matrix protein, forms both amyloid and non-amyloid fibrils. Non-amyloid TasA fibrils are formed via a strand-exchange mechanism, whereas the amyloid-like form involves non-specific self-assembly. We performed mutagenesis of the N-terminus to assess the role of non-amyloid fibrils in biofilm development. We find that the N-terminal tail is essential for the formation of structured biofilms, providing evidence that the strand-exchange fibrils are the active form in the biofilm matrix. Furthermore, we demonstrate that fibre formation alone is not sufficient to give structure to the biofilm. We build an interactome of TasA with other extracellular protein components, and identify important interaction sites. Our results provide insight into how protein-matrix interactions modulate biofilm development.
生物膜的细胞外基质为群落提供了至关重要的结构支撑，并使其免受环境干扰。枯草芽孢杆菌生物膜基质蛋白 TasA 既能形成淀粉样纤维，也能形成非淀粉样纤维。非淀粉样 TasA 纤维通过链交换机制形成，而类似淀粉样的形式则涉及非特异性自组装。我们对 N 端进行了突变，以评估非淀粉样纤维在生物膜发育中的作用。我们发现 N 端尾部对于形成有结构的生物膜是必需的，这为链交换纤维是生物膜基质中活性形式提供了证据。此外，我们证明仅纤维形成不足以赋予生物膜结构。我们构建了 TasA 与其他细胞外蛋白成分的相互作用组，并确定了重要的相互作用位点。我们的研究结果深入了解了蛋白质-基质相互作用如何调节生物膜的发育。
