Cyclic-di-GMP and ADP bind to separate domains of PilB as mutual allosteric effectors
Cyclic-di-GMP and ADP bind to separate domains of PilB as mutual allosteric effectors
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DOI：
10.1042/bcj20190809
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发表时间：
2020-01-01
影响因子：
4.1
通讯作者：
Yang, Zhaomin
中科院分区：
文献类型：
--
作者：
Dye, Keane J.;Yang, Zhaomin
PilB是细菌IV型菌毛（T4 P）的组装ATP酶，因此，它对于T4 P介导的细菌运动性是必需的。在一些情况下，已经证明PilB在细菌生物膜发育期间独立于或除了其在菌毛组装中的功能之外调节外泌多糖（EPS）的产生。虽然PilB的ATP酶活性存在于其C-末端区域，但PilB亚组的N末端形成新的环状二GMP（cdG）结合结构域。这种多结构域结构表明PilB通过单独的结构域结合cdG和腺嘌呤核苷酸，这可能影响PilB在运动性和生物膜发育中的功能。在这里，嗜热氯酸杆菌PilB用于研究其单独的结构域和全长蛋白质的配体结合。我们的研究结果证实了这些单独的结构域对各自配体的特异性，并证明了全长蛋白质中这些结构域之间的通信。很明显，当PilB的N-和C-末端结构域分别与cdG和ADP结合时，它们在构象和与配体的结合中相互影响。我们建议，这些结构域之间的相互作用，以响应其配体在调制或控制PilB的功能，作为一个调节器的EPS生产和T4 P组装ATP酶发挥关键作用。
PilB is the assembly ATPase for the bacterial type IV pilus (T4P), and as a consequence, it is essential for T4P-mediated bacterial motility. In some cases, PilB has been demonstrated to regulate the production of exopolysaccharide (EPS) during bacterial biofilm development independently of or in addition to its function in pilus assembly. While the ATPase activity of PilB resides at its C-terminal region, the N terminus of a subset of PilBs forms a novel cyclic-di-GMP (cdG)-binding domain. This multi-domain structure suggests that PilB binds cdG and adenine nucleotides through separate domains which may influence the functionality of PilB in both motility and biofilm development. Here, Chloracidobacterium thermophilum PilB is used to investigate ligand binding by its separate domains and by the full-length protein. Our results confirm the specificity of these individual domains for their respective ligands and demonstrate communications between these domains in the full-length protein. It is clear that when the N- and the C-terminal domains of PilB bind to cdG and ADP, respectively, they mutually influence each other in conformation and in their binding to ligands. We propose that the interactions between these domains in response to their ligands play critical roles in modulating or controlling the functions of PilB as a regulator of EPS production and as the T4P assembly ATPase.