Moss B, Koczot F
J Virol. 1976 Feb;17(2):385-92. doi: 10.1128/JVI.17.2.385-392.1976.
RNA labeled with [methyl-3H] methionine and [14C]uridine was isolated from the cytoplasm of adenovirus-infected cells and purified by poly(U)-Sepharose chromatography and hybridization to filters containing immobilized adeovirus DNA. Analysis by dimethyl sulfoxide-sucrose gradient sedimentation suggested that the major mRNA species were methylated. 7-Methylguanosine was identified at the 5'-terminus of the advenovirus-specific RNA and could be removed by periodate oxidation and beta-elimination. Structures of the type m7G(5')ppp(5')Nm containing the unusual nucleoside N6, O2'-dimethyladenosine, and smaller amounts of 2'-O-methyladenosine were isolated by DEAE-cellulose chromatography after P1 nuclease digestion of the RNA. Evidence for some 5'-terminal sequences, m7G(5')ppp(5')m6AmpNm, with additional 2'-O-methylribonucleosides was also obtained. A base-methylated nucleoside, N6-methyladenosine, is located within the RNA chain and is released as a mononucleotide by alkali hydrolysis.
用[甲基 - ³H]甲硫氨酸和[¹⁴C]尿苷标记的RNA从腺病毒感染细胞的细胞质中分离出来,并通过聚(U) - 琼脂糖凝胶柱层析以及与固定有腺病毒DNA的滤膜杂交进行纯化。通过二甲基亚砜 - 蔗糖梯度沉降分析表明,主要的mRNA种类被甲基化。在腺病毒特异性RNA的5'末端鉴定出7 - 甲基鸟苷,并且可以通过高碘酸盐氧化和β - 消除反应将其去除。在RNA经P1核酸酶消化后,通过DEAE - 纤维素柱层析分离出了含有异常核苷N⁶,O²'-二甲基腺苷以及少量2'-O - 甲基腺苷的m⁷G(5')ppp(5')Nm类型的结构。还获得了一些具有额外2'-O - 甲基核糖核苷的5'末端序列m⁷G(5')ppp(5')m⁶AmpNm的证据。一种碱基甲基化的核苷,N⁶ - 甲基腺苷,位于RNA链内,并通过碱水解以单核苷酸形式释放出来。