美国匹兹堡大学Graham F. Hatfull研究团队宣布他们研制了分枝噬菌体Bxb1的结构和感染动力学。2025年4月15日，国际知名学术期刊《细胞》发表了这一成果。

课题组人员报道了噬菌体Bxb1的完整结构和原子模型，包括衣壳和尾管亚基的免疫优势结构域的排列，以及尾尖复合物中蛋白质亚基的组装。该结构包含3倍、5倍、6倍和12倍对称的蛋白质组合，它们相互作用以满足几种对称不匹配。与耻垢分枝杆菌结合的噬菌体颗粒的低温电子断层扫描揭示了自由噬菌体颗粒与细胞表面结合，并穿过细胞壁以使DNA转移到细胞质中所发生的结构转变。

研究人员表示，分枝噬菌体Bxb1是耻垢分枝杆菌的一种具有双链DNA和长而灵活的尾巴的典型病毒。分枝杆菌噬菌体在治疗分枝杆菌感染方面显示出相当大的潜力，但对这些噬菌体的结构细节或它们如何结合和穿过复杂的分枝杆菌细胞壁知之甚少。

附：英文原文

Title: Structure and infection dynamics of mycobacteriophage Bxb1

Author: Krista G. Freeman, Sudipta Mondal, Lourriel S. Macale, Jennifer Podgorski, Simon J. White, Benjamin H. Silva, Valery Ortiz, Alexis Huet, Ronelito J. Perez, Joemark T. Narsico, Meng-Chiao Ho, Deborah Jacobs-Sera, Todd L. Lowary, James F. Conway, Donghyun Park, Graham F. Hatfull

Issue&Volume: 2025-04-15

Abstract: Mycobacteriophage Bxb1 is a well-characterized virus of Mycobacterium smegmatis with double-stranded DNA and a long, flexible tail. Mycobacteriophages show considerable potential as therapies for Mycobacterium infections, but little is known about the structural details of these phages or how they bind to and traverse the complex Mycobacterium cell wall. Here, we report the complete structure and atomic model of phage Bxb1, including the arrangement of immunodominant domains of both the capsid and tail tube subunits, as well as the assembly of the protein subunits in the tail-tip complex. The structure contains protein assemblies with 3-, 5-, 6-, and 12-fold symmetries, which interact to satisfy several symmetry mismatches. Cryoelectron tomography of phage particles bound to M. smegmatis reveals the structural transitions that occur for free phage particles to bind to the cell surface and navigate through the cell wall to enable DNA transfer into the cytoplasm.

DOI: 10.1016/j.cell.2025.03.027

Source: https://www.cell.com/cell/abstract/S0092-8674(25)00345-9