National Natural Science Foundation of China (NSFC)
U19A2020
中国
引用
ジャーナル: Proc Natl Acad Sci U S A / 年: 2025 タイトル: Cryo-EM structure of cyanopodophage A4 reveals a pentameric pre-ejectosome in the double-stabilized capsid. 著者: Pu Hou / Rui-Qian Zhou / Yong-Liang Jiang / Rong-Cheng Yu / Kang Du / Nanqin Gan / Fei Ke / Qi-Ya Zhang / Qiong Li / Cong-Zhao Zhou / 要旨: Upon infection, the podophages usually eject a couple of proteins from the capsid to form a transmembrane ejectosome on the host cell membrane that facilitates the ejection of viral genome. However, ...Upon infection, the podophages usually eject a couple of proteins from the capsid to form a transmembrane ejectosome on the host cell membrane that facilitates the ejection of viral genome. However, it remains unclear how these proteins of pre-ejectosome are finely assembled at the center of highly packaged genome. Here, we report the intact structure of cyanopodophage A4, which consists of a capsid stabilized by two types of cement proteins and a short tail attached with six tail fibers. Notably, we find a pentameric pre-ejectosome at the core of capsid, which is composed of four ejection proteins wrapped into a coaxial cylinder of triple layers. Moreover, a segment of genomic DNA runs along the positively charged circular cleft formed by two ejection proteins. Based on the mortise-and-tenon architecture of pre-ejectosome in combination with previous studies, we propose a putative DNA packaging process and ejection mechanism for podophages. These findings largely enrich our knowledge on the assembly mechanism of podophages, which might facilitate the application of A4 as a chassis cyanophage in synthetic biology.
A: Tail fiber protein B: Tail fiber protein C: Tail fiber protein D: Portal protein E: Portal protein F: Portal protein G: Portal protein H: Portal protein I: Portal protein J: Portal protein K: Portal protein L: Portal protein M: Portal protein N: Portal protein O: Portal protein P: Tail fiber protein Q: Tail fiber protein R: Tail fiber protein U: Tail tubular protein B V: Tail tubular protein B W: Tail tubular protein B X: Tail fiber protein Y: Tail fiber protein Z: Tail fiber protein a: Tail fiber protein b: Tail fiber protein c: Tail fiber protein d: Tail tubular protein A e: Tail tubular protein A f: Tail tubular protein A g: Tail tubular protein A h: Tail tubular protein A i: Tail tubular protein A j: Tail tubular protein A k: Tail tubular protein A l: Tail tubular protein A m: Tail tubular protein A n: Tail tubular protein A o: Tail tubular protein A p: Tail fiber protein q: Tail fiber protein r: Tail fiber protein u: Tail tubular protein B v: Tail tubular protein B w: Tail tubular protein B x: Tail fiber protein y: Tail fiber protein z: Tail fiber protein