Morris R O, Regier D A, Olson R M, Struxness L A, Armstrong D J
Biochemistry. 1981 Oct 13;20(21):6012-7. doi: 10.1021/bi00524a014.
The cytokinin-active isoprenoid nucleosides of Agrobacterium tumefaciens transfer ribonucleic acid were identified by high-pressure liquid chromatography, permethylation, and mass spectroscopy. Besides the expected 6-[(3-methylbut-2-enyl)amino]-9-(beta-D-ribofuranosyl)purine (i6A) and its 2-methylthio derivative (ms2i6A), substantial amounts of cis- and trans-ribosylzeatin (io6A) and cis-2-(methylthio)ribosylzeatin (c-ms2io6A) were present. These hydroxylated side chain derivatives are normally characteristic of plant tRNA. Fractionation of the total bacterial tRNA on BD-cellulose and RPC-5 allowed isolation of purified iso-accepting species whose cytokinin nucleoside contents were then determined. Distribution of the isoprenoid nucleosides among the U-group tRNA species was not uniform. cis-Ribosylzeatin was found almost exclusively in one tRNASer while ms2io6A was found predominantly in tRNAPhe, tRNASer, and tRNATyr. Not all cytokinin-active species were found in every member of the U-group tRNAs. The only species present in tRNATrp was i6A; it contained no zeatin derivatives. The hydroxylation and methylthiolation processes appear to be highly specific and dependent upon tRNA structure or sequence.
通过高压液相色谱、全甲基化和质谱法鉴定了根癌土壤杆菌转移核糖核酸中具有细胞分裂素活性的类异戊二烯核苷。除了预期的6-[(3-甲基丁-2-烯基)氨基]-9-(β-D-呋喃核糖基)嘌呤（i6A）及其2-甲硫基衍生物（ms2i6A）外，还存在大量的顺式和反式核糖基玉米素（io6A）和顺式-2-(甲硫基)核糖基玉米素（c-ms2io6A）。这些羟基化侧链衍生物通常是植物tRNA的特征。在BD-纤维素和RPC-5上对总细菌tRNA进行分级分离，可分离出纯化的同功受体种类，然后测定其细胞分裂素核苷含量。类异戊二烯核苷在U族tRNA种类中的分布并不均匀。顺式核糖基玉米素几乎只存在于一种tRNASer中，而ms2io6A主要存在于tRNAPhe、tRNASer和tRNATyr中。并非所有具有细胞分裂素活性的种类都存在于U族tRNA的每个成员中。tRNATrp中唯一存在的种类是i6A；它不含玉米素衍生物。羟基化和甲硫基化过程似乎具有高度特异性，并取决于tRNA的结构或序列。
