Bamford D H, Bamford J K, Towse S A, Thomas G J
Department of Genetics, University of Helsinki, Finland.
Biochemistry. 1990 Jun 26;29(25):5982-7. doi: 10.1021/bi00477a015.
The Raman spectrum of a virus contains the structural signature of each of its molecular components (Thomas, 1987). We report the first Raman spectrum obtained from an intact, lipid-containing virus--the icosahedral bacteriophage PRD1--and show that this spectrum contains characteristic structure markers for the major capsid protein, the packaged double-stranded DNA genome, and the viral membrane which resides between the capsid and DNA. We find that the packaged genome of PRD1 exhibits Raman markers typical of the B-DNA secondary structure. Comparison of the Raman spectrum of the packaged DNA with that of protein-free DNA extracted from the virion shows further that the B-form secondary structure is not significantly perturbed by packaging in the virion. The Raman signature of the PRD1 membrane, monitored within the virion at 4 degrees C, is that of a phospholipid liquid-crystalline phase. The PRD1 capsid, which comprises several hundred copies of the major coat protein P3 (product of viral gene III) and a few copies of minor proteins, incorporates P3 capsomers predominantly in the beta-sheet conformation. The beta-sheet structure of P3 is maintained in the fully assembled PRD1 virion, as well as in the empty capsid. The present results demonstrate the feasibility of obtaining structural information from the three different classes of biomolecules--nucleic acid, protein, and lipid--which constitute a membrane-lined virus particle. Our results also demonstrate that the coat protein and double-stranded DNA components of a lipid-containing bacteriophage share many structural features in common with bacteriophage lacking a lipid membrane.
病毒的拉曼光谱包含其每个分子成分的结构特征（托马斯，1987年）。我们报告了从完整的、含脂质的病毒——二十面体噬菌体PRD1获得的首个拉曼光谱，并表明该光谱包含主要衣壳蛋白、包装的双链DNA基因组以及位于衣壳和DNA之间的病毒膜的特征结构标记。我们发现PRD1的包装基因组呈现出典型的B-DNA二级结构的拉曼标记。将包装DNA的拉曼光谱与从病毒粒子中提取的无蛋白DNA的光谱进行比较进一步表明，B型二级结构在病毒粒子中的包装过程中没有受到显著干扰。在4摄氏度下在病毒粒子内监测到的PRD1膜的拉曼特征是磷脂液晶相的特征。PRD1衣壳由数百个主要衣壳蛋白P3（病毒基因III的产物）拷贝和少量次要蛋白拷贝组成，主要以β-折叠构象包含P3衣壳粒。P3的β-折叠结构在完全组装的PRD1病毒粒子以及空衣壳中均得以维持。目前的结果证明了从构成有膜病毒粒子的三类不同生物分子——核酸、蛋白质和脂质——中获取结构信息的可行性。我们的结果还表明，含脂质噬菌体的衣壳蛋白和双链DNA成分与缺乏脂质膜的噬菌体具有许多共同的结构特征。
