Plisson Celia, White Helen E, Auzat Isabelle, Zafarani Amineh, São-José Carlos, Lhuillier Sophie, Tavares Paulo, Orlova Elena V
School of Crystallography, Birkbeck College, University of London, London, UK.
EMBO J. 2007 Aug 8;26(15):3720-8. doi: 10.1038/sj.emboj.7601786. Epub 2007 Jul 5.
The majority of known bacteriophages have long noncontractile tails (Siphoviridae) that serve as a pipeline for genome delivery into the host cytoplasm. The tail extremity distal from the phage head is an adsorption device that recognises the bacterial receptor at the host cell surface. This interaction generates a signal transmitted to the head that leads to DNA release. We have determined structures of the bacteriophage SPP1 tail before and after DNA ejection. The results reveal extensive structural rearrangements in the internal wall of the tail tube. We propose that the adsorption device-receptor interaction triggers a conformational switch that is propagated as a domino-like cascade along the 1600 A-long helical tail structure to reach the head-to-tail connector. This leads to opening of the connector culminating in DNA exit from the head into the host cell through the tail tube.
大多数已知的噬菌体具有长长的非收缩性尾部（长尾噬菌体科），这些尾部充当将基因组递送至宿主细胞质的管道。远离噬菌体头部的尾部末端是一种吸附装置，可识别宿主细胞表面的细菌受体。这种相互作用产生一个传递到头部的信号，导致DNA释放。我们已经确定了噬菌体SPP1在DNA喷射前后的尾部结构。结果揭示了尾管内壁广泛的结构重排。我们提出，吸附装置与受体的相互作用触发了一种构象转换，这种转换沿着1600埃长的螺旋状尾部结构以多米诺骨牌式的级联方式传播，到达头尾连接体。这导致连接体打开，最终使DNA通过尾管从头部进入宿主细胞。
