6PSH

Crystal structure of periplasmic domain of antiholin RI from T4 phage

6PSH の概要

• エントリーDOI: 10.2210/pdb6psh/pdb
• 分子名称: Antiholin, 1,2-ETHANEDIOL (3 entities in total)
• 機能のキーワード: phage, lysis inhibition, viral protein
• 由来する生物種: Enterobacteria phage T4
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 10390.67

構造登録者

Kuznetsov, V.B.,Krieger, I.V.,Sacchettini, J.C. (登録日: 2019-07-12, 公開日: 2020-06-24, 最終更新日: 2024-10-30)

主引用文献

Krieger, I.V.,Kuznetsov, V.,Chang, J.Y.,Zhang, J.,Moussa, S.H.,Young, R.F.,Sacchettini, J.C.
The Structural Basis of T4 Phage Lysis Control: DNA as the Signal for Lysis Inhibition.
J.Mol.Biol., 432:4623-4636, 2020

PubMed Abstract: Optimal phage propagation depends on the regulation of the lysis of the infected host cell. In T4 phage infection, lysis occurs when the holin protein (T) forms lesions in the host membrane. However, the lethal function of T can be blocked by an antiholin (RI) during lysis inhibition (LIN). LIN sets if the infected cell undergoes superinfection, then the lysis is delayed until host/phage ratio becomes more favorable for the release of progeny. It has been thought that a signal derived from the superinfection is required to activate RI. Here we report structures that suggest a radically different model in which RI binds to T irrespective of superinfection, causing it to accumulate in a membrane as heterotetrameric 2RI-2T complex. Moreover, we show the complex binds non-specifically to DNA, suggesting that the gDNA from the superinfecting phage serves as the LIN signal and that stabilization of the complex by DNA binding is what defines LIN. Finally, we show that soluble domain of free RI crystallizes in a domain-swapped homotetramer, which likely works as a sink for RI molecules released from the RI-T complex to ensure efficient lysis. These results constitute the first structural basis and a new model not only for the historic LIN phenomenon but also for the temporal regulation of phage lysis in general.

PubMed: 32562709
DOI: 10.1016/j.jmb.2020.06.013

実験手法

X-RAY DIFFRACTION (2.21 Å)