Kakefuda T, Bader J P
J Virol. 1969 Oct;4(4):460-74. doi: 10.1128/JVI.4.4.460-474.1969.
The ribonucleic acid (RNA) of murine leukemia virus (MLV) Rauscher strain was observed by the aid of electron microscopy with the use of the protein monolayer technique. RNA was observed directly after release from virus particles or after isolation by sedimentation in sucrose density gradients. Molecules were found in an extended linear form. Many of the RNA filaments released by detergent treatment contained curled regions, suggesting the linear filaments were originally coiled within the virus particle. The relationship of the curled areas to the containment of the RNA within the virus particle is discussed, and a mechanism for the inclusion of RNA in the budding virion is proposed. Treatment of the extended MLV-RNA with dimethyl sulfoxide resulted in the collapse of the molecule forming a tangled complex. Treatment with urea or heating at 50 C in 3 mm NaCl also produced this effect. Also under the conditions in which MLV-RNA was linear, RNA from Rous sarcoma virus also was linear, but Newcastle disease virus RNA and ribosomal RNA of rat liver had collapsed structures. The results indicated that the RNA of MLV, and perhaps other RNA-containing tumor viruses, has a specific unique conformation dependent upon hydrogen bonds.
借助蛋白质单层技术，通过电子显微镜观察了劳氏肉瘤病毒（Rauscher strain）鼠白血病病毒（MLV）的核糖核酸（RNA）。RNA在从病毒颗粒释放后或通过蔗糖密度梯度沉降分离后直接进行观察。发现分子呈伸展的线性形式。经去污剂处理释放的许多RNA细丝含有卷曲区域，这表明线性细丝最初是盘绕在病毒颗粒内的。讨论了卷曲区域与RNA在病毒颗粒内的容纳之间的关系，并提出了RNA包含在出芽病毒体中的机制。用二甲基亚砜处理伸展的MLV-RNA会导致分子塌陷形成缠结复合物。用尿素处理或在3 mM NaCl中于50℃加热也会产生这种效果。同样在MLV-RNA呈线性的条件下，劳斯肉瘤病毒的RNA也是线性的，但新城疫病毒RNA和大鼠肝脏的核糖体RNA具有塌陷结构。结果表明，MLV的RNA以及可能其他含RNA的肿瘤病毒具有依赖于氢键的特定独特构象。
