Justus-Liebig-Universität, Department of Microbiology and Molecular Biology, 35392, Giessen, Germany.
Department of Molecular Biology II, Centre for Medical Biotechnology (ZMB), University of Duisburg-Essen, 45141, Essen, Germany.
NPJ Biofilms Microbiomes. 2022 May 2;8(1):35. doi: 10.1038/s41522-022-00297-w.
In bacteria, the monopolar localization of enzymes and protein complexes can result in a bimodal distribution of enzyme activity between the dividing cells and heterogeneity of cellular behaviors. In Shewanella putrefaciens, the multidomain hybrid diguanylate cyclase/phosphodiesterase PdeB, which degrades the secondary messenger c-di-GMP, is located at the flagellated cell pole. Here, we show that direct interaction between the inactive diguanylate cyclase (GGDEF) domain of PdeB and the FimV domain of the polar landmark protein HubP is crucial for full function of PdeB as a phosphodiesterase. Thus, the GGDEF domain serves as a spatially controlled on-switch that effectively restricts PdeBs activity to the flagellated cell pole. PdeB regulates abundance and activity of at least two crucial surface-interaction factors, the BpfA surface-adhesion protein and the MSHA type IV pilus. The heterogeneity in c-di-GMP concentrations, generated by differences in abundance and timing of polar appearance of PdeB, orchestrates the population behavior with respect to cell-surface interaction and environmental spreading.
在细菌中，酶和蛋白质复合物的单极定位可能导致酶活性在分裂细胞之间呈双峰分布，并导致细胞行为的异质性。在脱硫弧菌中，多结构域混合二鸟苷酸环化酶/磷酸二酯酶 PdeB 降解第二信使 c-di-GMP，位于鞭毛细胞极。在这里，我们表明 PdeB 的无活性二鸟苷酸环化酶 (GGDEF) 结构域与极性地标蛋白 HubP 的 FimV 结构域之间的直接相互作用对于 PdeB 作为磷酸二酯酶的充分功能至关重要。因此，GGDEF 结构域充当空间控制的开启开关，有效地将 PdeB 的活性限制在鞭毛细胞极。PdeB 调节至少两种关键表面相互作用因子的丰度和活性，即 BpfA 表面粘附蛋白和 MSHA 型 IV 菌毛。由 PdeB 丰度和极性出现时间的差异产生的 c-di-GMP 浓度的异质性协调了与细胞表面相互作用和环境扩散有关的种群行为。
