National Institutes of Health/National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIH/NIAMS)
米国
Russian Foundation for Basic Research
16-34-60137
ロシア
Biotechnology and Biological Sciences Research Council
BB/L021250/1
英国
Wellcome Trust
108466
英国
引用
ジャーナル: Proc Natl Acad Sci U S A / 年: 2019 タイトル: Cryo-EM structure and in vitro DNA packaging of a thermophilic virus with supersized T=7 capsids. 著者: Oliver W Bayfield / Evgeny Klimuk / Dennis C Winkler / Emma L Hesketh / Maria Chechik / Naiqian Cheng / Eric C Dykeman / Leonid Minakhin / Neil A Ranson / Konstantin Severinov / Alasdair C ...著者: Oliver W Bayfield / Evgeny Klimuk / Dennis C Winkler / Emma L Hesketh / Maria Chechik / Naiqian Cheng / Eric C Dykeman / Leonid Minakhin / Neil A Ranson / Konstantin Severinov / Alasdair C Steven / Alfred A Antson / 要旨: Double-stranded DNA viruses, including bacteriophages and herpesviruses, package their genomes into preformed capsids, using ATP-driven motors. Seeking to advance structural and mechanistic ...Double-stranded DNA viruses, including bacteriophages and herpesviruses, package their genomes into preformed capsids, using ATP-driven motors. Seeking to advance structural and mechanistic understanding, we established in vitro packaging for a thermostable bacteriophage, P23-45 of Both the unexpanded procapsid and the expanded mature capsid can package DNA in the presence of packaging ATPase over the 20 °C to 70 °C temperature range, with optimum activity at 50 °C to 65 °C. Cryo-EM reconstructions for the mature and immature capsids at 3.7-Å and 4.4-Å resolution, respectively, reveal conformational changes during capsid expansion. Capsomer interactions in the expanded capsid are reinforced by formation of intersubunit β-sheets with N-terminal segments of auxiliary protein trimers. Unexpectedly, the capsid has T=7 quasi-symmetry, despite the P23-45 genome being twice as large as those of known T=7 phages, in which the DNA is compacted to near-crystalline density. Our data explain this anomaly, showing how the canonical HK97 fold has adapted to double the volume of the capsid, while maintaining its structural integrity. Reconstructions of the procapsid and the expanded capsid defined the structure of the single vertex containing the portal protein. Together with a 1.95-Å resolution crystal structure of the portal protein and DNA packaging assays, these reconstructions indicate that capsid expansion affects the conformation of the portal protein, while still allowing DNA to be packaged. These observations suggest a mechanism by which structural events inside the capsid can be communicated to the outside.
#200 - 2016年8月 正二十面体型ウイルスの準対称性 (Quasisymmetry in Icosahedral Viruses) 類似性 (1)
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集合体
登録構造単位
A: Major head protein B: Major head protein C: Major head protein D: Major head protein E: Major head protein F: Major head protein G: Major head protein
A: Major head protein B: Major head protein C: Major head protein D: Major head protein E: Major head protein F: Major head protein G: Major head protein
x 60
complete icosahedral assembly
根拠: mass spectrometry, LC-MS/MS of purified capsids
A: Major head protein B: Major head protein C: Major head protein D: Major head protein E: Major head protein F: Major head protein G: Major head protein
x 5
icosahedral pentamer
1.63 MDa, 35 ポリマー
分子量 (理論値)
分子数
合計 (水以外)
1,633,826
35
ポリマ-
1,633,826
35
非ポリマー
0
0
水
0
タイプ
名称
対称操作
数
identity operation
1_555
x,y,z
1
point symmetry operation
4
4
A: Major head protein B: Major head protein C: Major head protein D: Major head protein E: Major head protein F: Major head protein G: Major head protein