Riechmann L, Holliger P
MRC Laboratory of Molecular Biology, Cambridge, United Kingdom.
Cell. 1997 Jul 25;90(2):351-60. doi: 10.1016/s0092-8674(00)80342-6.
Filamentous bacteriophages infecting gram-negative bacteria display tropism for a variety of pilus structures. However, the obligatory coreceptor of phage infection, postulated from genetic studies, has remained elusive. Here we identify the C-terminal domain of the periplasmic protein TolA as the coreceptor for infection of Escherichia coli by phage fd and the N-terminal domain of the phage minor coat protein g3p as its cognate ligand. The neighboring g3p domain binds the primary receptor of phage infection, the F pilus, and blocks TolA binding in its absence. Contact with the pilus releases this blockage during infection. Our findings support a sequential two-way docking mechanism for phage infection, analogous to infection pathways proposed for a range of eukaryotic viruses including herpes simplex, adenoviruses, and also lentiviruses like HIV-1.
感染革兰氏阴性菌的丝状噬菌体对多种菌毛结构表现出嗜性。然而，从遗传学研究推测的噬菌体感染的必需共受体一直难以捉摸。在这里，我们确定周质蛋白TolA的C末端结构域是噬菌体fd感染大肠杆菌的共受体，噬菌体次要外壳蛋白g3p的N末端结构域是其同源配体。相邻的g3p结构域结合噬菌体感染的主要受体F菌毛，并在没有F菌毛时阻止TolA结合。在感染过程中，与菌毛的接触解除了这种阻断。我们的发现支持了噬菌体感染的顺序双向对接机制，类似于包括单纯疱疹病毒、腺病毒以及HIV-1等慢病毒在内的一系列真核病毒所提出的感染途径。
