ジャーナル: Structure / 年: 2022 タイトル: Structure and assembly pattern of a freshwater short-tailed cyanophage Pam1. 著者: Jun-Tao Zhang / Feng Yang / Kang Du / Wei-Fang Li / Yuxing Chen / Yong-Liang Jiang / Qiong Li / Cong-Zhao Zhou / 要旨: Despite previous structural analyses of bacteriophages, quite little is known about the structures and assembly patterns of cyanophages. Using cryo-EM combined with crystallography, we solve the near- ...Despite previous structural analyses of bacteriophages, quite little is known about the structures and assembly patterns of cyanophages. Using cryo-EM combined with crystallography, we solve the near-atomic-resolution structure of a freshwater short-tailed cyanophage, Pam1, which comprises a 400-Å-long tail and an icosahedral capsid of 650 Å in diameter. The outer capsid surface is reinforced by trimeric cement proteins with a β-sandwich fold, which structurally resemble the distal motif of Pam1's tailspike, suggesting its potential role in host recognition. At the portal vertex, the dodecameric portal and connected adaptor, followed by a hexameric needle head, form a DNA ejection channel, which is sealed by a trimeric needle. Moreover, we identify a right-handed rifling pattern that might help DNA to revolve along the wall of the ejection channel. Our study reveals the precise assembly pattern of a cyanophage and lays the foundation to support its practical biotechnological and environmental applications.