Structure and interactions of the single-stranded DNA genome of filamentous virus fd: investigation by ultraviolet resonance raman spectroscopy.
Structure and interactions of the single-stranded DNA genome of filamentous virus fd: investigation by ultraviolet resonance raman spectroscopy.
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丝状病毒 fd 单链 DNA 基因组的结构和相互作用：紫外共振拉曼光谱研究。
DOI：
10.1021/bi970342q
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
ThomasJr,GJ
中科院分区：
文献类型：
--
作者：
Wen,ZQ;Overman,SA;ThomasJr,GJ
丝状噬菌体是传染性支气管炎病毒Ff类的成员，包括噬菌体f1和m13。用激发波长257、244、238和229 nm获得了紫外共振拉曼(UVRR)光谱。在257 nm处的激发选择性地增强了包装的单链(Ss)DNA基因组的拉曼标记，而在较短波长处的激发有利于检测来自外壳蛋白芳香族化合物的拉曼信号，特别是病毒外壳亚单位(Pviii)的色氨酸(W26)和酪氨酸残基(Y21和Y24)。主要发现如下： (1)包装基因组的da、dc、dg和dt残基在257和244 nm处的UVRR光谱中识别出了独特的标记，尽管病毒粒子的质量组成较低(12%)。(2)包装后的单链DNA碱基的拉曼光谱显示出异常共振的拉曼减色效应。观察到了高达母DNA核苷酸强度80%的拉曼强度损失。这被解释为广泛的短程相互作用的证据，涉及包装基因组的碱基。(3)反之，外壳蛋白的色氨酸和酪氨酸残基的拉曼谱带一般表现出较强的增色。通常，芳香氨基酸的拉曼标记在UVRR光谱中的强度大约是游离氨基酸光谱中的3倍。残基Y21、Y24和W26的非常高的拉曼截面表明病毒组件中的异常疏水环境。(4)从H2O到D2O溶液转移过程中的UVRR谱带移动表明，包装的单链DNA的碱基很容易被溶剂交换。N1H→N1D交换实验表明，W26分子中的吲哚N1H基团在D2O溶液中也可被溶剂访问。(5)包装的fdDNA基因组的UVRR标记证实了先前从非共振拉曼研究中得出的结论，即fdDNA核苷有利于C3‘-Endo/反构象，而不是代表DNA最低能量结构的C2’-Endo/反构象。我们得出结论，包装后的fd基因组的核苷构象受到天然病毒粒子组装中ssDNA和外壳蛋白亚基的特定组织的影响。
The filamentous bacteriophagefdis a member of theFfclass ofInovirus, which includes phagesf1andM13. Ultraviolet resonance Raman (UVRR) spectra offdhave been obtained using excitation wavelengths of 257, 244, 238, and 229 nm. Excitation at 257 nm selectively enhances Raman markers of the packaged single-stranded (ss) DNA genome, while excitation at the shorter wavelengths favors the detection of Raman signals from coat protein aromatics, particularly tryptophan (W26) and tyrosine residues (Y21 and Y24) of the viral coat subunit (pVIII). The principal findings are the following: (1) Distinctive markers of dA, dC, dG, and dT residues of the packaged genome are identified in UVRR spectra offdexcited at 257 and 244 nm, despite the low DNA mass composition (12%) of the virion. (2) Raman bands of the bases of packaged ssDNA show extraordinary resonance Ramanhypochromism. Raman intensity losses as large as 80% of the parent DNA nucleotide intensities are observed. This is interpreted as evidence of extensive short-range interactions involving bases of the packaged genome. (3) Conversely, Raman bands of tryptophan and tyrosine residues of the coat protein generally exhibit stronghyperchromism. Typically, Raman markers of the aromatic amino acids are about 3-fold more intense in the UVRR spectrum offdthan in spectra of the free amino acids. The very high Raman cross sections for residues Y21, Y24, and W26 are indicative of unusual hydrophobic environments in the viral assembly. (4) UVRR band shifts that accompany the transfer offdfrom H2O to D2O solution indicate that bases of the packaged ssDNA are readily exchanged by the solvent. Similarly, the indole N1H group of W26 is accessible to solvent, as shown by N1H → N1D exchange in D2O solution. (5) The UVRR markers of the packagedfdgenome confirm the conclusion reached previously from off-resonance Raman studies thatfdDNA nucleosides favor the C3‘-endo/anticonformation, rather than the C2‘-endo/anticonformation that is characteristic of the lowest energy structure of DNA. We conclude that nucleoside conformations of the packagedfdgenome are influenced by the specific organization of ssDNA and coat protein subunits in the native virion assembly.