Structure of the bacteriophage T4 long tail fiber receptor-binding tip
Structure of the bacteriophage T4 long tail fiber receptor-binding tip
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DOI：
10.1073/pnas.1011218107
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发表时间：
2010-11-23
影响因子：
11.1
通讯作者：
van Raaij, Mark J.
中科院分区：
文献类型：
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作者：
Bartual, Sergio G.;Otero, Jose M.;van Raaij, Mark J.
噬菌体是生物圈中数量最多的生物。尽管它们具有生物学意义和潜在的应用范围，但它们的受体结合纤维的高分辨率结构细节很少。在这里，我们展示了噬菌体T4长尾纤维的受体结合尖端的晶体结构，它与噬菌体λ侧尾纤维的尖端高度同源。该结构揭示了一个不寻常的细长的六链反平行β -链针结构域，其中包含七个铁离子，这些铁离子由沿生物单元核心共线排列的组氨酸残基协调。在尖端的末端，三个链相互缠绕形成一个更宽的头部结构域，其中包含假定的受体相互作用位点。该结构揭示了以前未知的β结构纤维折叠，提供了对纤维显著稳定性的见解，并提出了突变扩展或调节受体结合特异性的框架。
Bacteriophages are the most numerous organisms in the biosphere. In spite of their biological significance and the spectrum of potential applications, little high-resolution structural detail is available on their receptor-binding fibers. Here we present the crystal structure of the receptor-binding tip of the bacteriophage T4 long tail fiber, which is highly homologous to the tip of the bacteriophage lambda side tail fibers. This structure reveals an unusual elongated six-stranded antiparallel beta-strand needle domain containing seven iron ions coordinated by histidine residues arranged colinearly along the core of the biological unit. At the end of the tip, the three chains intertwine forming a broader head domain, which contains the putative receptor interaction site. The structure reveals a previously unknown beta-structured fibrous fold, provides insights into the remarkable stability of the fiber, and suggests a framework for mutations to expand or modulate receptor-binding specificity.