Central European Institute of Technology, Kamenice 753/5, 625 00, Brno, Czech Republic.
Faculty of Science, Masaryk University, Kamenice 753/5, 625 00, Brno, Czech Republic.
Nat Commun. 2022 Sep 24;13(1):5622. doi: 10.1038/s41467-022-33305-w.
Escherichia coli phage SU10 belongs to the genus Kuravirus from the class Caudoviricetes of phages with short non-contractile tails. In contrast to other short-tailed phages, the tails of Kuraviruses elongate upon cell attachment. Here we show that the virion of SU10 has a prolate head, containing genome and ejection proteins, and a tail, which is formed of portal, adaptor, nozzle, and tail needle proteins and decorated with long and short fibers. The binding of the long tail fibers to the receptors in the outer bacterial membrane induces the straightening of nozzle proteins and rotation of short tail fibers. After the re-arrangement, the nozzle proteins and short tail fibers alternate to form a nozzle that extends the tail by 28 nm. Subsequently, the tail needle detaches from the nozzle proteins and five types of ejection proteins are released from the SU10 head. The nozzle with the putative extension formed by the ejection proteins enables the delivery of the SU10 genome into the bacterial cytoplasm. It is likely that this mechanism of genome delivery, involving the formation of the tail nozzle, is employed by all Kuraviruses.
大肠杆菌噬菌体 SU10 属于短尾噬菌体目长尾噬菌体科的 Kuravirus 属，其尾部短且不可收缩。与其他短尾噬菌体不同，Kuravirus 的尾部在附着到细胞时会延长。在这里，我们展示了 SU10 病毒粒子具有拉长的头部，包含基因组和喷出蛋白，以及由门户、适配体、喷口和尾针蛋白组成的尾部，并装饰有长纤维和短纤维。长尾纤维与外细胞膜中的受体结合，诱导喷口蛋白的伸直和短尾纤维的旋转。重新排列后，喷口蛋白和短尾纤维交替排列形成一个喷口，使尾部延长 28nm。随后，尾针从喷口蛋白上脱离，SU10 头部释放出五种类型的喷出蛋白。带有推测的由喷出蛋白形成的延伸的喷口使 SU10 基因组能够进入细菌细胞质。很可能，所有 Kuravirus 都采用了这种涉及尾喷口形成的基因组传递机制。
