CIRCULAR FORMS OF UUKUNIEMI VIRION RNA - ELECTRON-MICROSCOPIC STUDY
CIRCULAR FORMS OF UUKUNIEMI VIRION RNA - ELECTRON-MICROSCOPIC STUDY
复制标题
DOI：
10.1128/jvi.21.3.1085-1093.1977
复制
发表时间：
1977-01-01
影响因子：
5.4
通讯作者：
BALTIMORE, D
中科院分区：
文献类型：
--
作者：
HEWLETT, MJ;PETTERSSON, RF;BALTIMORE, D
由于Uukuniemi病毒基因组片段的核糖核蛋白形式先前被表征为环状，因此在增加变性的条件下通过EM检查分离的RNA。在适度变性条件（50或60%甲酰胺）下展开后，50-70%的分子是环状的。将甲酰胺浓度增加到70%和85%减少了环状形式的数量，并且在60 ℃温育RNA后仅观察到线性形式。在99%甲酰胺中搅拌15分钟。当从4 M尿素-80%甲酰胺（另一种已知使RNA变性的条件）展开时，仅观察到5-30%的环状分子。在37 ℃下用0.5M乙二醛预处理RNA。在从50%甲酰胺展开之前，在室温下搅拌15分钟，得到< 5%的圆形形式。分子的长度测量表明，它们没有被所采用的任何方法显著降解。用胰腺RNA酶[EC 3.1.4.22]处理可破坏环状分子，但不受DNA酶[EC 3.1.4.5]或蛋白酶K处理的影响。在RNA完全变性后，环可以在再退火条件下重新形成。构成Uukuniemi病毒基因组的3种大小类别的RNA是环状分子，可能通过线性分子3“和5”末端的反向互补序列之间的碱基配对而保持该形式。
Because the ribonucleoprotein forms of the segments of the Uukuniemi virus genome were previously characterized as circular, the isolated RNA were examined by EM under conditions of increasing denaturation. After spreading under moderately denaturing conditions (50 or 60% formamide), 50-70% of the molecules were circular. Increasing the formamide concentration to 70 and 85% decreased the number of circular forms, and only linear forms were observed after incubation of the RNA at 60.degree. C for 15 min in 99% formamide. When spread from 4 M urea-80% formamide, another condition known to denature RNA, only 5-30% circular molecules were observed. Pretreatment of the RNA with 0.5 M glyoxal at 37.degree. C for 15 min prior to spreading from 50% formamide gave < 5% circular forms. Length measurement of the molecules showed that they were not significantly degraded by any of the methods employed. The circular molecules were destroyed by treatment with pancreatic RNase [EC 3.1.4.22], but were unaffected by DNase [EC 3.1.4.5] or proteinase K treatment. After complete denaturation of the RNA, the circles could be reformed under reannealing conditions. The 3 size classes of RNA that comprise the Uukuniemi virus genome are circular molecules probably maintained in that form by base pairing between inverted complementary sequences at the 3'' and 5'' ends of linear molecules.