Staphylococcus aureus phage 80alpha-derived SaPI1 mature capsid. Sharpened map used for model fitting and refinement. Map sharpened with bsoft by application of inverse Bfactor = 800.
試料
ウイルス: Staphylococcus phage 80alpha (ファージ)
タンパク質・ペプチド: Major head protein
キーワード
major capsid protein / HK97-like fold / mature capsid / VIRUS
機能・相同性
Phage capsid / Phage capsid family / viral capsid / Major capsid protein
National Institutes of Health/National Institute Of Allergy and Infectious Diseases (NIH/NIAID)
R01AI083255
米国
引用
ジャーナル: Viruses / 年: 2017 タイトル: Cleavage and Structural Transitions during Maturation of Staphylococcus aureus Bacteriophage 80α and SaPI1 Capsids. 著者: James L Kizziah / Keith A Manning / Altaira D Dearborn / Erin A Wall / Laura Klenow / Rosanne L L Hill / Michael S Spilman / Scott M Stagg / Gail E Christie / Terje Dokland / 要旨: In the tailed bacteriophages, DNA is packaged into spherical procapsids, leading to expansion into angular, thin-walled mature capsids. In many cases, this maturation is accompanied by cleavage of ...In the tailed bacteriophages, DNA is packaged into spherical procapsids, leading to expansion into angular, thin-walled mature capsids. In many cases, this maturation is accompanied by cleavage of the major capsid protein (CP) and other capsid-associated proteins, including the scaffolding protein (SP) that serves as a chaperone for the assembly process. bacteriophage 80α is capable of high frequency mobilization of mobile genetic elements called pathogenicity islands (SaPIs), such as SaPI1. SaPI1 redirects the assembly pathway of 80α to form capsids that are smaller than those normally made by the phage alone. Both CP and SP of 80α are N-terminally processed by a host-encoded protease, Prp. We have analyzed phage mutants that express pre-cleaved or uncleavable versions of CP or SP, and show that the N-terminal sequence in SP is absolutely required for assembly, but does not need to be cleaved in order to produce viable capsids. Mutants with pre-cleaved or uncleavable CP display normal viability. We have used cryo-EM to solve the structures of mature capsids from an 80α mutant expressing uncleavable CP, and from wildtype SaPI1. Comparisons with structures of 80α and SaPI1 procapsids show that capsid maturation involves major conformational changes in CP, consistent with a release of the CP N-arm by SP. The hexamers reorganize during maturation to accommodate the different environments in the 80α and SaPI1 capsids.
#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 (2)
-
マップ
ファイル
ダウンロード / ファイル: emd_7333.map.gz / 形式: CCP4 / 大きさ: 92.1 MB / タイプ: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES)
注釈
Staphylococcus aureus phage 80alpha-derived SaPI1 mature capsid. Sharpened map used for model fitting and refinement. Map sharpened with bsoft by application of inverse Bfactor = 800.