ジャーナル: Nat Commun / 年: 2023 タイトル: The ϕPA3 phage nucleus is enclosed by a self-assembling 2D crystalline lattice. 著者: Eliza S Nieweglowska / Axel F Brilot / Melissa Méndez-Moran / Claire Kokontis / Minkyung Baek / Junrui Li / Yifan Cheng / David Baker / Joseph Bondy-Denomy / David A Agard / 要旨: To protect themselves from host attack, numerous jumbo bacteriophages establish a phage nucleus-a micron-scale, proteinaceous structure encompassing the replicating phage DNA. Bacteriophage and host ...To protect themselves from host attack, numerous jumbo bacteriophages establish a phage nucleus-a micron-scale, proteinaceous structure encompassing the replicating phage DNA. Bacteriophage and host proteins associated with replication and transcription are concentrated inside the phage nucleus while other phage and host proteins are excluded, including CRISPR-Cas and restriction endonuclease host defense systems. Here, we show that nucleus fragments isolated from ϕPA3 infected Pseudomonas aeruginosa form a 2-dimensional lattice, having p2 or p4 symmetry. We further demonstrate that recombinantly purified primary Phage Nuclear Enclosure (PhuN) protein spontaneously assembles into similar 2D sheets with p2 and p4 symmetry. We resolve the dominant p2 symmetric state to 3.9 Å by cryo-EM. Our structure reveals a two-domain core, organized into quasi-symmetric tetramers. Flexible loops and termini mediate adaptable inter-tetramer contacts that drive subunit assembly into a lattice and enable the adoption of different symmetric states. While the interfaces between subunits are mostly well packed, two are open, forming channels that likely have functional implications for the transport of proteins, mRNA, and small molecules.
根拠: 電子顕微鏡法, PhuN forms 2D crystals when applied to glow-discharged grids for negative stain EM at a pH of 6.5. Via cryoEM, PhuN has been observed to assemble into large 2D lattices ...根拠: 電子顕微鏡法, PhuN forms 2D crystals when applied to glow-discharged grids for negative stain EM at a pH of 6.5. Via cryoEM, PhuN has been observed to assemble into large 2D lattices with the help of lattice supports., microscopy, In the associated publication and previously published work, fluorescence microscopy has shown the PhuN protein assembles into a large structure inside infected cells.
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#1: タンパク質
... Maltose/maltodextrin-bindingperiplasmicprotein, phiPA3PhuN / MMBP / Maltodextrin-binding protein / Maltose-binding protein / MBP / ChmA / Phage nucleus ...MMBP / Maltodextrin-binding protein / Maltose-binding protein / MBP / ChmA / Phage nucleus enclosure protein / PhuN / gene product 53 / gp53