ジャーナル: Proc Natl Acad Sci U S A / 年: 2023 タイトル: Fine structure and assembly pattern of a minimal myophage Pam3. 著者: Feng Yang / Yong-Liang Jiang / Jun-Tao Zhang / Jie Zhu / Kang Du / Rong-Cheng Yu / Zi-Lu Wei / Wen-Wen Kong / Ning Cui / Wei-Fang Li / Yuxing Chen / Qiong Li / Cong-Zhao Zhou / 要旨: The myophage possesses a contractile tail that penetrates its host cell envelope. Except for investigations on the bacteriophage T4 with a rather complicated structure, the assembly pattern and tail ...The myophage possesses a contractile tail that penetrates its host cell envelope. Except for investigations on the bacteriophage T4 with a rather complicated structure, the assembly pattern and tail contraction mechanism of myophage remain largely unknown. Here, we present the fine structure of a freshwater cyanophage Pam3, which has an icosahedral capsid of ~680 Å in diameter, connected via a three-section neck to an 840-Å-long contractile tail, ending with a three-module baseplate composed of only six protein components. This simplified baseplate consists of a central hub-spike surrounded by six wedge heterotriplexes, to which twelve tail fibers are covalently attached via disulfide bonds in alternating upward and downward configurations. In vitro reduction assays revealed a putative redox-dependent mechanism of baseplate assembly and tail sheath contraction. These findings establish a minimal myophage that might become a user-friendly chassis phage in synthetic biology.
A: Major capsid B: Major capsid C: Major capsid D: Major capsid E: Major capsid F: Major capsid G: Cement H: Cement I: Cement J: Cement K: Cement L: Cement M: Cement N: Major capsid