The molecular mechanism of the type IVa pilus motors.
The molecular mechanism of the type IVa pilus motors.
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DOI：
10.1038/ncomms15091
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发表时间：
2017-05-05
影响因子：
16.6
通讯作者：
Howell PL
中科院分区：
文献类型：
--
作者：
McCallum M;Tammam S;Khan A;Burrows LL;Howell PL
IVa型皮利是许多细菌病原体中对毒力至关重要的蛋白质细丝;它们从细菌细胞表面延伸和缩回以将细菌向前拉。马达ATP酶PilB为菌毛组装提供动力。在这里，我们报告的核心ATP酶结构域的Geetrimetallreducens PilB绑定到ADP和不可水解的ATP类似物，AMP-PNP，在3.4和2.3 μ m分辨率，分别。这些结构揭示了链之间核苷酸结合的重要差异。对这些差异的分析揭示了核苷酸的顺序更替以及相应的结构域运动。我们的数据表明，顺时针旋转的PilB，通过与PilC的相互作用，将支持组装的右手螺旋菌毛的中心子孔。我们的分析还表明，C2对称PilT的逆时针旋转，这将使右手菌毛拆卸。所提出的模型提供了深入了解这个家庭的ATP酶可以电源菌毛的延伸和收缩。IVa型细菌的皮利是用于运动和蛋白质分泌的蛋白质细丝。在这里，作者提出了两种核苷酸状态下的Geatomymetallereducens PilB ATP酶的晶体结构，并建议PilB的中心子孔顺时针旋转，这将支持右手螺旋菌毛的组装。
Type IVa pili are protein filaments essential for virulence in many bacterial pathogens; they extend and retract from the surface of bacterial cells to pull the bacteria forward. The motor ATPase PilB powers pilus assembly. Here we report the structures of the core ATPase domains of Geobacter metallireducens PilB bound to ADP and the non-hydrolysable ATP analogue, AMP-PNP, at 3.4 and 2.3 Å resolution, respectively. These structures reveal important differences in nucleotide binding between chains. Analysis of these differences reveals the sequential turnover of nucleotide, and the corresponding domain movements. Our data suggest a clockwise rotation of the central sub-pores of PilB, which through interactions with PilC, would support the assembly of a right-handed helical pilus. Our analysis also suggests a counterclockwise rotation of the C2 symmetric PilT that would enable right-handed pilus disassembly. The proposed model provides insight into how this family of ATPases can power pilus extension and retraction. Bacterial type IVa pili are protein filaments used for motility and protein secretion. Here the authors present crystal structures of the Geobacter metallireducens PilB ATPase in two nucleotide states, and suggest a clockwise rotation of the central sub-pores of PilB that would support the assembly of a right-handed helical pilus.